U.S. patent number 3,990,980 [Application Number 05/505,522] was granted by the patent office on 1976-11-09 for hybrid liquid toners.
This patent grant is currently assigned to Philip A. Hunt Chemical Corporation. Invention is credited to George E. Kosel.
United States Patent |
3,990,980 |
Kosel |
* November 9, 1976 |
Hybrid liquid toners
Abstract
A hybrid liquid toner composed of a mixture of two different
types of liquid toner. One type is a liquid toner that includes a
complex amphipathic molecule of which at least a fixer and a
dispersant are polymeric moieties and which additionally includes a
charge director and optionally includes a color agent, all of these
being carried by a volatile organic solvent of high electrical
resistivity. The other type of liquid toner is one that includes a
fixer and a dispersant as separate chemical entities and further
includes a charge director, a pigment type color agent and a
carrier solvent such as mentioned above. The two toners can be
mixed in a very wide range of proportions and when so mixed have
several advantages which makes the hybrid toner particularly useful
in connection with preparation of lithographic masters and
microfiche reproductions by electrostatography as well as useful as
an all purpose liquid toner.
Inventors: |
Kosel; George E. (Park Ridge,
NJ) |
Assignee: |
Philip A. Hunt Chemical
Corporation (Palisades Park, NJ)
|
[*] Notice: |
The portion of the term of this patent
subsequent to August 21, 1990 has been disclaimed. |
Family
ID: |
27029783 |
Appl.
No.: |
05/505,522 |
Filed: |
September 12, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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433251 |
Jan 15, 1974 |
|
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163502 |
Jul 16, 1971 |
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Current U.S.
Class: |
430/113; 430/116;
430/904; 430/114; 524/902 |
Current CPC
Class: |
C08F
8/00 (20130101); G03G 9/12 (20130101); G03G
9/133 (20130101); Y10S 430/105 (20130101); Y10S
524/902 (20130101) |
Current International
Class: |
C08F
8/00 (20060101); G03G 9/13 (20060101); G03G
9/12 (20060101); G03G 009/12 () |
Field of
Search: |
;252/62.1 ;260/22R,33.6R
;96/1LY ;427/15,17 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Weinblatt; Mayer
Assistant Examiner: Smith; John D.
Attorney, Agent or Firm: Kirschstein, Kirschstein, Ottinger
& Frank
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 433,251
filed Jan. 14, 1974 for HYBRID LIQUID TONERS, the latter
application being an improvement over applications Serial No.
810,841 (now abandoned) filed Mar. 26, 1969 for LIQUID TONERS, and
Ser. No. 7253 filed Jan. 30, 1970 for LIQUID TONERS (now U.S. Pat.
No. 3,753,760 dated Aug. 21, 1973); and is a continuation of
application Ser. No. 163,502 (now abandoned) filed July 16, 1971
for HYBRID LIQUID TONERS.
Claims
Having thus described the invention, there is claimed as new and
desired to be secured by Letters Patent:
1. A liquid electrostatographic toner consisting essentially of a
combination of:
A. a first liquid toner including
i. a solvent system having an evaporation rate at least as fast as
that of kerosene, but slower than that of hexane, and a
Kauri-butanol number less than 35, is substantially
aromatic-liquid-free, has an electrical resistivity of at least
about 10.sup.9 ohm centimeters, a dielectric constant of less than
three and one half and a Tagliabue closed cup flash point of at
least 100.degree. F, is non-toxic and non-polar, has no
objectionable odor, and has a viscosity of between 0.5 and 2.5
centipoises at room temperature,
Ii. a solid synthetic thermoplastic fixer dissolved in the solvent
system and
iii. a dispersant;
B. a second liquid toner including
i. a solvent system compatible with the first liquid toner and
which has an evaporation rate at least as fast as that of kerosene,
but slower than that of hexane, and a Kauributanol number less than
35, is substantially aromatic-liquid-free, has an electrical
resistivity of at least about 10.sup.9 ohm centimeters, a
dielectric constant of less than three and one half and a Tagliabue
closed cup flash point of at least 100.degree. F, is non-toxic and
non-polar, has no objectionable odor, and has a viscosity of
between 0.5 and 2.5 centipoises at room temperature,
ii. an amphipathic polymeric molecule of the graft type having a
polymeric backbone part and a polymeric graft part on said backbone
part, said molecule being composed of two polymeric moieties of
which at least one is thermoplastic, said first polymeric moiety,
which is one of said parts, being solvated by said systems, a
portion of said first polymeric moiety being a fixative and a
dispersant, and a second polymeric moiety, which is the other of
said parts, being insoluble in said systems, said second polymeric
moiety having a particle size between 25 m.mu. and 25.mu., a
portion of said second polymeric moiety being a fixative, so that
there is provided a continuous phase constituting the solvent
systems with the first polymeric moiety dissolved therein and a
dispersed phase constituting the non-solvated polymeric moiety
whereby said molecule acts as a mono-dispersed particle phase, a
fixative and a dispersant;
C. the first liquid toner being present in an amount of from 0.5%
to 99.5%, the balance of the liquid electrostatographic toner being
the second liquid toner; and
D. at least one of said liquid toners including a charge
director.
2. A liquid electrostatographic toner as set forth in claim 1
wherein the second liquid toner further includes a color agent.
3. A liquid electrostatographic toner as set forth in claim 2
wherein the color agent is a moiety of the amphipathic
molecule.
4. A liquid electrostatographic toner as set forth in claim 2
wherein the color agent is a compound other than the amphipathic
molecule.
5. A liquid electrostatographic toner as set forth in claim 1
wherein the amphipathic molecule includes a solvated polymeric
moiety selected from the group consisting of: crepe rubber; refined
linseed oil, degraded rubber; alkyd resins; polyisobutylene;
polybutadiene; polyisoprene, polyisobornyl methacrylate;
homopolymeric vinyl esters of long chain fattey acids;
homopolymeric vinyl alkyl ethers; homopolymers of the C.sub.4
-C.sub.22 alkyl esters of acrylic and methacrylic acid in a
molecular weight range of about 10.sup.3 to about 10.sup.6 ;
copolymers of the aforesaid C.sub.4 -C.sub.22 alkyl esters with one
another; copolymers of the aforesaid C.sub.4 -C.sub.22 alkyl esters
with one another and with methyl, ethyl, isopropyl and propyl
esters of acrylic and methacrylic acids; copolymers of the C.sub.4
-C.sub.22 alkyl esters of acrylic and methacrylic acids with
monomers containing acrylic acid, methacrylic acid, crotonic acid,
maleic acid, atropic acid, fumaric acid, itaconic acid, citraconic
acid, acrylic anhydride, methacrylic anhydride, maleic anhydride,
acryloyl chloride, methacryloyl chloride, acrylonitrile,
methacrylonitrile, N-vinyl pyrrolidone, acrylaminde and derivatives
thereof, methacrylamide and derivatives thereof, hydroxyethyl
methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate,
hydroxypropyl acrylate, dimethylaminomethyl methacrylate,
dimethylaminomethyl acrylate, dimethylaminoethyl methacrylate,
dimethylaminoethyl acrylate, diethylaminomethyl methacrylate,
diethylaminomethyl acrylate, diethylaminoethyl methacrylate,
diethylaminoethyl acrylate, t-butylaminoethyl methacrylate,
t-butylaminoethyl acrylate, cyclohexyl acrylate, allyl alcohol and
derivatives thereof, cinnamic acid and derivatives thereof, styrene
and derivatives thereof, butadiene, methallyl alcohol and
derivatives thereof, propargyl alcohol and derivatives thereof,
indene and derivatives thereof, norbornene and derivatives thereof,
vinyl ethers, vinyl esters, vinyl derivatives other than vinyl
ethers and vinyl esters, glycidyl methacrylate and acrylate, mono-
and dimethyl maleate, mono- and diethyl maleate, mono-n-butyl
maleate, mono-sec-butyl maleate, mono-ter-butyl maleate, monobenzyl
maleate, mono-2-ethylhexyl maleate, mono-n-octyl maleate, mono- and
dimethyl fumarate and mono- and diethyl fumarate; condensation
polymers; copolymers of butadiene, isoprene and isobutylene with
c.sub.4 -C.sub.22 alkyl esters of acrylic and methacrylic acids;
polycarbonates; polyamides; polyurethanes and epoxies, and the
nonsolvated polymeric moiety comprises homopolymers and copolymers
formed from monomers selected from the group consisting of vinyl
acetate, vinyl chloride, methyl acrylate, methyl methacrylate,
ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl
methacrylate, isopropyl acrylate, isopropyl methacrylate, hydroxy
ethyl acrylate, hydroxy ethyl methacrylate, hyydroxy propyl
acrylate, hydroxy propyl methacrylate, acrylonitrile,
methacrylonitrile, acrylamide, methacrylamide, acrylic acid,
acrylic anhydride, methacrylic acid, methacrylic anhydride, mono
methyl maleate, mono ethyl maleate, mono-n-butyl maleate,
mono-sec-butyl maleate, mono-ter-butyl maleate, mono-2-ethylehexyl
maleate, mono-n-octyl maleate, mono methyl fumarate, mono-ethyl
fumarate, styrene, vinyl toluene, maleic acid, maleic anhydride,
crotonic acid, crotonic anhydride, fumaric acid, atropic acid,
allylamine, vinyl amine, allyl alcohol, vinyl pyridines and
derivatives thereof, glycidyl acrylate, glycidyl methacrylate,
dialkylaminoalkyl methacrylate, dialkylaminoalkyl acrylate,
methacrylyl acetone, N-hydroxymethyl methacrylamides, alkoxymethyl
methacrylamides, acryloyl chloride, methacryloyl chloride, vinyl
isocyanate, cyanomethylacrylate, vinyl .beta.-chloroethylsulphone,
vinyl sulphonic acid, monobenzyl maleate and vinyl phosphoric
acid.
6. A liquid electrostatographic toner as set forth in claim 1
wherein the amphipathic molecule includes a backbone chain of
comonomers and attached chains having attached sites of a precursor
monomer derived from monomers selected from the affiliated monomer
groups set forth below:
7. A liquid electrostatographic toner as set forth in claim 1
wherein the charge director is selected from the group consisting
of: di-2-ethylhexyl sodium sulfosuccinate; di-tridecyl sodium
sulfosuccinate; aluminum, chromium, zinc and calcium salts of
3,5-dialkylsalicylic acid, wherein the alkyl group is propyl,
isopropyl, butyl, isobutyl, tertiary butyl, amyl, isoamyl and other
alkyl groups up to C-18; aluminum, chromium, zinc and calcium salts
of dialkyl gamma-resorcylic acid, wherein the alkyl is as above;
isopropylamine salt of dodecylbenzene sulfonic acid; aluminum,
vanadium and tin dresinates; cobalt, iron, lithium, tin and
manganese octoates; a partially imidized polyamine with
lubricating-oil soluble polyisobutylene chains and free secondary
amines, gravity at 60.degree. F. API 22.9, specific 0.92, flash
point by the Cleveland open cup method, 425.degree. F., viscosity
at 210.degree. F., 400 SSU, color (ASTM D-1500) L55D, nitrogen
percentage by weight 2.0, and alkalinity value, (SM-205-15) 43;
soya bean lecithin; aluminum salt of 50--50 by weight mixture of
the mono- and di-2 ethylhexyl esters of phosphoric acid; zinc,
lead, copper, cadmium, calcium, aluminum and iron stearates; zinc
and aluminum palmitates; aluminum oleate; copper, manganese, cobalt
and lead linoleates; manganese linoresinate; and
1-[2-hydroxyethyl]-2-[mixed pentadecyl and
heptadecyl]-2-imidazoline.
8. A liquid electrostatographic toner as set forth in claim 1
wherein the solid synthetic thermoplastic fixer is selected from
the group consisting of: polymerized and hydrogenated thermoplastic
acidic wood rosin, glycerol ester of modified wood rosin,
pentaerythritol ester of wood rosin, pentaerythritol ester of
polymerized wood rosin, modified pentaerythritol ester of wood
rosin, pentaerythritol ester of hydrogenated wood rosin,
pentaerythritol ester of dimeric resin acids, modified
pentaerythritol ester of wood rosin, glycerol ester of polymerized
wood rosin, a thermoplastic petroleum hydrocarbon resin in which
the units of the polymer are predominantly selected from the group
consisting of aromatic and cyclic units, having an acid number of
less than 1 and a softening point of 100.degree. C by the ring and
ball method, fully hydrogenated glycerol ester of wood rosin,
internally plasticized pentaerythritol ester of wood rosin, dimeric
resin acids, a vinyl toluene/acrylate copolymer, and a vinyl
toluene/n-butyl methacrylate/stearyl methacrylate polymer.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
A hybrid liquid toner composed of a mixture of two toners, one of
which includes an amphipathic molecule composed of various
polymeric moieties having different functions at least one of which
is a fixing function and another is a dispersant function, and a
second liquid toner which includes no amphipathic molecule but does
include a fixer and a dispersant as separate chemical entities,
preferably at least one of the toners including a color agent, and
the hybrid toner further including a charge director, and an
organic volatile liquid carrier solvent of high electrical
resistivity.
2. Description of the Prior Art
A conventional prior art liquid toner typically was composed of a
volatile organic liquid solvent system of high electrical
resistivity in which there were carried several constituents, some
being dispersed and others being dispersed or solvated.
Exemplificatively, these other constituents were: a thermoplastic
fixer, a dispersant, a pigment which frequently was carbon black,
and a charge director, all of these being separate chemical
entitles. This type of prior art toner will be referred to
hereinafter as a "first" liquid toner.
A second type of liquid toner has been proposed in application Ser.
No. 810,841 (now abandoned) filed Mar. 26, 1969 for LIQUID TONERS,
and in application Ser. No. 7253 filed Jan. 30, 1970 for LIQUID
TONERS (now U.S. Pat. No. 3,753,760) which is a
continuation-in-part of application Ser. No. 810,841. This latter
liquid toner will hereinafter be referred to as the "second" liquid
toner. The second liquid toner was characterized by the presence
therein of an amphipathic molecule which as at least one polymeric
moiety thereof included a thermoplastic fixer and as at least
another polymeric thereof a dispersant plastic fixer and as at
least another polymeric thereof a dispersant so that these two
moieties formed part of a single chemical entity which was complex
molecule. The amphipathic molecule could also include as another
polymeric moiety thereof a color agent or the color agent could be
a chemically separate entity in the second liquid toner.
Furthermore, the second liquid toner included a charge director
which was not part of the amphipathic molecule. Like the first
liquid toner, the second liquid toner additionally included a
liquid carrier which was a volatile organic solvent system of high
electrical resistivity. Of the said one polymeric moiety and the
said another polymeric moiety, at least one is thermoplastic. The
said one polymeric moiety is soluble in the solvent system and a
portion thereof is a fixative and a dispersant. The said another
polymeric moiety is insoluble in the solvent system and has a
particle size between 25 m.mu. and 25.mu., a portion of said
another polymeric moiety being a fixative. Thereby the second type
of liquid toner has a continuous phase constituting the solvent
system with the said polymeric moiety dissolved therein and a
dispersed phase constituting the said another polymeric moiety so
that the amphiphathic molecule acts as a mono-dispersed particle
phase, a fixative and a dispersant.
Each of these two liquid toners had certain advantages and each had
certain disadvantages, the disadvantages of the second liquid toner
being comparatively minor but nevertheless existent. These
disadvantages, and particularly the disadvantages of the second
liquid toner, were not important factors in the use of the second
liquid toner for most electrostatographic purposes such, for
instance, as one of the most widespread applications thereof which
constituted its employment in an office copying machine. However,
the minor disadvantages of the second liquid toner did to some
extent hinder its use in connection with the preparation of
lithographic masters and of reproductions for microfiche purposes
by an electrostatographic process.
Thus, it has been found that where the second liquid toner was used
for making a lithographic master, although the master could be used
for a large number of runs, for instance over 15,000, when the runs
were considerably longer there was a tendency for the
electrostatographically deposited image to deteriorate.
Electrostatographic lithographic masters are prepared by
electrostatographically depositing a toner either with or without a
color-agent on a flexible base which is covered with a
photoconductor coating that has had formed therein a latent
electrostatic image and subsequently is developed by applying a
liquid toner thereto. Both the photoconductor coating and the
deposited toner image are oleophilic and to render the image and
its carrier useful as a master the background areas having no
deposits thereon must be rendered oleophobic which is accomplished
by making them hydrophilic. This transformation is effected by a
swabbing technique which, for example, employs a water solution of
ferrocyanide or ferricyanide as an etchant that attacks the portion
of the photoconductor coating which does not bear the
electrostatographically deposited image. The photoconductor
conventionally used in this technique is zinc oxide in a resin
binder, this being a commercial electrostatographic paper.
In connection with the preparation of lithographic masters (as well
as for general purposes) with the use of the first liquid toner, a
serious disadvantage was present which occurred where the original
to be reproduced contained one or more colored (non-white) areas of
appreciable size, for instance in excess of 1/4inch in any
dimension. In such cases there was a marked tendency for the
deposit of toner on the area to be of greater density adjacent the
periphery than at the center. This drawback did not attend the use
of the second liquid toner.
As to electrostatographic microfiche reproductions there was a
minor disadvantage accompanying the use of the second liquid toner
which was that there was a tendency, which might be caused by the
large size of the complex molecule, for the boundary line of the
image to waver slightly, i.e. to deviate slightly and almost
unnoticeably from a faithful reproduction of the boundary line of
the original. this disadvantage affected the ability to form a good
enlargement of the microfiche image.
A far more serious disadvantage associated with the use of
electrostatographic reproduction of microfiche images and which was
inherent in the use of the first liquid toner was the difficulty in
fixing the electrostatographically deposited image on the carrier.
The carrier included a transparent thermoplastic filmforming
material containing a transparent photoconductor which was utilized
to form the latent electrostatic image, the same subsequently being
developed. One such photoconductor which was widely used was a
poly-N-vinyl carbazole. After the image had been deposited it had
to be fixed. This fixing was accomplished by heating, but, since
the film-forming material tended to become dimensionally unstable
at approximately the temperature employed for fusing the image,
there was a marked tendency for the image to distort which was
unacceptable for microfiche luses.
SUMMARY OF THE INVENTION
1. Purposes of the Invention
It is an object of the present invention to provide an unique
hybrid liquid toner which is not subject ot any of the foregoing
defects.
It is another objects of the invention to provide a hydrib liquid
toner which is capable of being employed in electrostatographic
formation of a lithographic master that is capable of extended
runs, well in excess of 15,000 reproductions, without
deterioration.
It is another object of the invention to provide a hybrid liquid
toner of the character described which has a good "fill" of
solid-colored areas and yet is capable of being treated to enable
the same to be used as a lithographic master.
It is another object of the invention to provide a hydrid liquid
toner of the character described which is particularly useful for
the preparation of microfiche images by electrostatographic
processes and wherein the resolution is exceedingly good and heat
fixing can be achieved without disturbing the dimensional stability
of the transparent thermoplastic which constitutes the support for
the developed image.
It is another object of the invention to provide a hydrid liquid
toner of the character described which, in addition to being useful
for the aforesaid purposes, can, without any modification
whatsoever, be employed for conventional office copying purposes in
any type of equipment using a liquid toner, thereby enabling the
same toner to be employed universally for all kinds and types of
purposes.
Indeed, it is an ancillary object of the invention to provide a
hybrid liquid toner of the character described which can be used in
any system in which a liquid toner of any kind can be employed as,
for instance, in ink jet recording, for cathode ray tube read-outs
and in conjunction with light beam writing, as well as cathode ray
pin tubes and various types of transfer processes such as pressure
transfer, vacuum transfer and electrostatic transfer.
2. Brief Description of the Invention
In general, the invention is carried out by combining two liquid
toners utilizing, basically, functionally different systems, the
two toners being admixable in an extremely wide range of
proportions, exemplificatively as little as 0.5% of either the
first or second liquid toner with the balance of the hybrid toner
constituting the other liquid toner. As will be pointed out in the
specific description, there are various advantages to be gained by
adjusting these proportions in either direction.
The first toner is the type which, as of the date of this
application, is known as a "conventional" toner and it includes as
a liquid carrier a volatile organic solvent system of high
electrical resistivity, e.g. at least about 10.sup.9 ohms
centimeters. This liquid carrier has therein a fixer which may
either be dispersed or solvated, a dispersant which usually is
solvated, a charge director which may be solvated or dispersed and
a pigment such, for instance, as carbon black which conventionally
is dispersed.
The second liquid toner is of the type disclosed in the aforesaid
patent applications Ser. Nos. 810,841 (now abandoned) and 7253 (now
U.S. Pat. No. 3,753,760) These generally include a solvent system
such as the one used for the first toner. The solvent system has
therein a complex amphipathic molecule that at least includes as
polymeric moieties thereof a fixer and a dispersant and which may
include as an additional moiety a color agent. The color agent may
also be present in the second toner as a separate chemical entity,
i.e. not part of the complex amphipathic molecule. The color agent
is not necessarily present in either the first or the second liquid
toner, although it is desirably employed. For example, it does not
have to be included if the hybrid toner is to be used exclusively
in the formation of a lithographic master although, even under such
circumstances, its presence is desirable. Furthermore, the second
toner includes a charge director which is not part of the
amphipathic molecule.
When the two toners are admixed with the use of any conventional
mixing equipment such, for instance, as a blender, a ball mill, a
batch stirrer or a homogenizer, or even manually stirred, a hybrid
toner is created which is particularly useful for forming
lithographic masters and microfiche reproductions
electrostatographically and is also useful as a general purpose
electrostatographic developer both in ordinary business copy
machines of all kinds and in the special type of equipment
hereinbefore briefly alluded to, to wit, ink jet printers, cathode
ray tube printers, light beam writing printers and transfer
printers. Instead of preparing the two toners separately and then
combining them, the ingredients for both toners can be mixed at the
same time. The hybrid toner preferably includes a common solvent
system and may include a common charge director(s) and color
agent(s). Furthermore, the amphipathic molecule of the second
liquid toner may be used as the dispersant for the first liquid
toner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Any conventional prior art first liquid toner can be employed. Such
a toner includes a volatile organic liquid solvent system having a
high electrical resistivity of at least about 10.sup.9 ohms
centimeters.
Preferably, the solvent system includes one or more solvents of the
petroleum type such a solvent commonly being referred to as a
"petroleum fraction". This includes distilation fractions,
catalytically cracked fractions and polymers of aliphatic monomers
derived either synthetically or by distillation or cracking
fractionation. Petroleum fractions are particularly useful in
connection with the first toner because of the following
attributes:
(a) quick evaporation, e.g., a thin film of the carrier will
evaporate in a few seconds at a temperature below the char point of
paper, so as to permit fast drying; (b) non-toxicity; (c) low odor;
(d) the characteristic that when employed with soluble solid
film-forming agents it will fully escape therefrom so as to leave
the solid film deposited by such agent tack-free and not subject to
evaporation over protracted periods of time after the deposited
image is seemingly dry; (e) sufficient fluidity to allow the
particles of pigment to migrate therethrough with ease so that the
pigment is capable of being quickly electrostatically attracted to
and coupled with the pattern of electrostatic charges which is to
be developed; (f) not attacking the coating binders on a base sheet
and not attacking other ingredients of the sheet; (g) not bleeding
the electrostatic charges before the pigment is deposited so as to
maintain any desired degree of contrast; and (h)
inexpensiveness.
In order to obtain these beneficial attributes, the petroleum
fraction, i.e., paraffinic solvent, should have an evaporation rate
at least as fast as that of kerosene, but slower than that of
hexane. Thereby, the evaporation of the liquid from a film will be
rapid, e.g., two seconds, at a temperature slightly below the char
point of paper, it being frequently customary to raise the
temperature of the film of liquid developer to this level for the
purpose of evaporating the developer after the opaque electroscopic
particles of pigment have been deposited by attraction on the
electrostatically charged pattern. The petroleum fraction should
have a low K. B. (Kauri-butanol) number, to wit, less than 35, and
preferably between 26 and 35. This low K. B. number minimizes the
possibility that the petroleum fraction will attack the coating
binder, e.g., the binder for the zinc oxide, or will attack any
sizing on the sheet, e.g., paper, upon which the coating is
applied. The petroleum fraction also should be substantially free
of aromatic liquid constituents, i.e., it should be substantially
aromatic-liquid-free. This term, as used herein, connotes that the
proportion of aromatic liquids in the organic liquid carrier should
not be in excess of two per cent by weight. The aromatic liquids
have a strong tendency to attack the coating binders, e.g., the
coating binders for zinc oxide, but in concentrations of less than
two per cent this tendency is so negligible as to be unnoticeable.
The petroleum fraction must have a high electrical resistivity,
e.g., in the order of at least about 10.sup.9 ohm centimeters, and
a dielectric constant of less than three and one-half, so that the
liquid carrier will not dissipate the pattern of electrostatic
charges which are to be developed. The TCC (Tagliabue closed cup)
flash point of the liquid carrier should be at least 100.degree. F
and preferably about 120.degree. to 152.degree. F, whereby under
the conditions of use the liquid is considered non-flammable. The
paraffinic solvent also is non-toxic. It possesses no objectionable
odor and preferably is odor-free, this being denoted by the term
"low odor". Consonant with its low dielectric constant and high
resistivity, the liquid carrier is non-polar. The solvent system
should have a low viscosity for the purpose, as indicated above, of
permitting rapid migration therethrough of opaque electroscopic
charged pigment particles which are to be attracted in large number
to the electrostatically charged image which is to be developed.
Such viscosity should be between 0.5 and 2.5 centripoises at room
temperature. The petroleum fraction also is inexpensive.
Examples of petroleum fraction organic liquid carriers having
physical characteristics which fall within the foregoing criteria
are Shell Sol 71, manufactured by Shell Oil Company; Isopar G,
Isopar H, Isopar K, and Isopar L, manufactured by Humble Oil and
Refining Company; Amsco OMS, Amsco 460 Solvent and Amsco Odorless
Insecticide Base manufactured by American Mineral Spirits Company;
and odorless kerosene. All of the foregoing are low odor paraffinic
solvents. The dielectric constant of Shell Sol 71 is 2.06 at room
temperatures. The other solvents have dielectric constants of the
same order of magnitude. Other physical characteristics of Shell
Sol 71, Isopar G, Isopar H, Isopar K, Isopar L, Amsco OMS, Amsco
460 Solvent and Amsco Odorless Insecticide Base which fingerprint
these solvents and denote the presence of several of the above
listed attributes are set forth below:
______________________________________ Distillation Flash Pt. IBP*
Dry End Sp. Gr. Pt. .degree. F. K.B. Aniline 60.degree./60.degree.
.degree. F. .degree. F. TCC No. Pt. .degree. F. F.
______________________________________ Shell Sol 71 345 398 121
26.5 183 0.7563 Isopar G 318 347 105 28.0 178 0.748 Isopar H 350
371 123 26.9 183 0.7571 Isopar K 349 383 126 26.5 185 0.7587 Isopar
L 372 406 144 -- 187 0.7674 Amsco OMS 352 386 125 27.0 184.5 0.7608
Amsco 460 Solvent 375 456 150 34.5 146.5 0.8108 Amsco Odorless
Insecticide Base 375 482 152 26.5 175.0 0.7711
______________________________________ *Initial Boiling Point ASTM
D-1078
The second constituent of the first liquid toner is the fixer which
may be dispersible or soluble in the organic solvent system. The
fixer acts as a film-forming agent in the developed image, holding
the pigment bound to the carrier sheet. The fixing agent is solid
at room temperatures and in the absence of a solvent therefor. The
fixing agent, if soluble in the solvent system, preferably is fully
soluble therein and has a good solvent release characteristic,
which is to say, it must permit the solvent system to evaporate
completely and quickly through a solid coherent film-like deposit
left as a residue after solvent evaporation. The film left by the
fixer either with or without heating of the deposited fixer, as the
case may be, must be tackfree, tough and coherent so that the
developed image will not smear or shred and will be resistent to
deterioration. Moreover, the fixer should be compatible with the
binder for the photoconductor coating, e.g. with the binder for a
photoconductor zinc oxide coating, and should bond well to said
coating in order to avoid any tendency of the finished image to
separate or peel from the coated sheet. The following constitute
excellent fixers, some of these being of the solvatable type and
others being of the non-solvatable type:
Resin NC 11, manufactured by Hercules Powder Company. This is a
pale thermoplastic acidic wood rosin that has been both polymerized
and hydrogenated. It has a softening point of 85.degree. to
93.degree. C by the Hercules drop method and an acid number of
145-65. Its density at 20.degree. c is 1.065. It has a
saponification number of 155-165. Its degree of hydrogenation is
about 90% and it has an average molecular wieght of 360. About 20%
of the rosin acids are polymerized.
______________________________________ * Manu- Acid Softening Resin
facturer Description No. Pt. .degree. C
______________________________________ Lewisol 7 Hercules Glycerol
ester of modified wood rosin 8 168 HDM Pentalyn A Hercules
Pentaerythritol ester of wood rosin 12 111 HDM Pentalyn C Hercules
Pentaerythritol ester of poly- merized wood rosin 14 135 HDM
Pentalyn G Hercules Modified penta- erythritol ester of wood rosin
14 135 HDM Pentalyn H Hercules Pentaerythritol ester of hydro-
genated wood rosin 13 104 HDM Pentalyn K Hercules Pentaerythritol
ester of dimeric resin acids 14 192 HDM Pentalyn X Hercules
Modified penta- erythritol ester of wood rosin 14 159 HDM Pentalyn
Hercules Pentaerythritol 860 ester of dimeric resin acids 15 172
HDM Polypale Hercules Glycerol ester Ester 10 of polymerized wood
rosin 6 112 HDM Staybelite Hercules Hydrogenated Resin wood rosin
165 76 HDM Krumbhaar Lawter Pentaerythritol <1 180-190 MM 484
Chemicals, ester of modi- Inc., Krum- fied wood rosin bhaar Resin
Division Nevehem Neville 100 Chemical + Company
______________________________________ * HDM--Hercules Drop Method
MM--Mercury Method R&B--Ring and Ball
+A thermoplastic petroleum hydrocarbon resin in which the units in
the polymer are predominantly aromatic or cyclic in structure. It
is prepared by the polymerization of unsaturated hydrocarbon
fractions boiling between about 125.degree. and about 250.degree.
C, having a Sp. Gr. (15.6/15.6.degree. C) of between 0.90 and 0.95.
The polymerizable constituents comprise between about 30% to 90% by
weight and the principal polymerizable monomers are:
______________________________________ cyclodiene dimers** 5-30%
indene 5-20% vinyl toluene 5-25% styrene 0-10%
______________________________________ **Such as dicyclopentadiene
(C.sub.10); di-methylcyclopentadiene (C.sub.12) codimer of
cyclopentadiene and methylcyclopentadiene (C.sub.11).
The balance dry weight of the hydrocarbon fraction is constituted
of essentially unpolymerizable paraffins, napthenes and aromatics
containing 8 or more carbon atoms per molecule and boiling within
the aforementioned range, i.e., between about 125.degree. and
250.degree. C. The unsaturated hydrocarbon fractions from which the
resin is obtained come from high temperature and low pressure
pyrolysis of normally liquid or gaseous hydrocarbons having 2 or
more carbon atoms per molecule. The cracking operation may be
by-products of pyrolytic processes in which the principal products
sought are low boiling olefines and dienes such as ethylene,
propylene, butenes, butadiene, etc. which are widely used base
hydrocarbons in the petrochemical and plastics fields including
elastomers. Pyrolysis of both liquid and gaseous hydrocarbons for
such purposes is well known and need not be described in
detail.
______________________________________ Nevchem 100 Test Property
(Typical Properties) 1. Softening Point (R&B) .degree. C. 100
2. Molecular Weight (No. Ave) 800 3. C/H Weight ratio 10.5 4. Sp.
Gr. 25/25.degree. C. 1.090 5. Refr. Index 25.degree. C/D 1.602 6.
Iodine Number 65 7. Acid Number <1 List of Test Methods: 1. ASTM
E-28-58-T 2. Osmotic 3. Combustion Analysis 4. ASTM D-71-52 5.
Neville Method (toluene solution, extrapolated to solid resin) 6.
ASTM D-555 ______________________________________
______________________________________ Acid Softening Resin
Manufacturer Description No. Pt. .degree. C.
______________________________________ Foral 85 Hercules Fuly
hydro- genated glycerol ester of wood rosin 9 82 HDM Cellolyn
Hercules Internally 104 plasticized pentaerythritol ester of wood
rosin 30 101 HDM Dymerex Hercules Dimeric resin acids 143 152 HDM
Pliolite Goodyear Vinyl toluene/ VTAC-L acrylate copolymer 6.1 47
R&B Neocryl Polyvinyl Vinyl toluene/ B-707 Chemicals n-butyl
metha- crylate/stearyl methacrylate (disclosed in USLP 3,378,513,
Example 23) 115 R&B ______________________________________
All the foregoing fixers except the last two are solvatable in one
or more of the above listed organic solvents; the last two are not
solvatable in most of said solvents but can be employed therewith
in disperse form for the first liquid toner.
The third constituent of the first liquid toner is a dispersant
which may either be solvatable in the solvent system or
non-solvatable; conventionally the dispersant is solvatable in said
solvent system. The function of the dispersant, as is well known,
is to disperse the pigment particles of sub-micron range in the
non-polar solvent system that is employed. The dispersant must be
compatible with the fixer and desirably is or includes a fixer in
its own right. Desirably, also, the dispersant will augment the
charge direction of the pigment particles.
Examples of solid dispersants having the foregoing physical
characteristics are: Lube Oil 564 and FOA 2. Lube Oil 564 is
manufactured by du Pont and is composed of 50% of methacrylate
polymer and 50% of kerosene. Insofar as the above examples of
dispersants are concerned, it is the solid constituents that
constitutes the dispersant, the liquid carrier merely forming a
convenient vehicle therefor. Other dispersants include: Alkanol DOA
manufactured by duPont and constituting an oil additive
constituting a terpolymer prepared from a weight mixture of 50
parts of octadecenyl methacrylate, 10 parts diethylaminoethyl
methacrylate, and 40 parts styrene, the same being polymerized by
conventional bulk, solution or dispersion polymerization methods
involving known initiators including oxygen-yielding compounds,
such as benzoyl peroxide, and azo compounds such as alpha, alpha'
azodiisobutyronitrile. The polymerization process preferably is
carried out in an inert atmosphere, for example, nitrogen or carbon
dioxide, at conventional temperatures ranging, as is well known,
from 30.degree. to 150.degree. C, depending on the catalyst used,
and generally between 50.degree. to 70.degree. C where the catalyst
is alpha, alpha' azodiisobutyronitrile. The polymerization is
carried substantially to completion to eliminate substantially all
of the unpolymerized monomers, it being understood that
"substantially to completion" as used herein denotes that there is
a remainder of from 0% to 15% of total monomers. The aforesaid
terpolymer is dissolved in kerosene in proportions of 50% by weight
of the terpolymer to 50% by weight of kerosene. The terpolymer
constitutes, as is seen, several completely organic compounds
combined in proportions to effect the optimum balance between
polar-active and oil-soluble groups. The said terpolymer is large
and has an average molecular weight of 50,000.
Still other dispersants that may be used are those disclosed in
U.S. Pat. No. 3,048,544, namely alkyl methacrylate maleic anhydride
polymer, maleimide polymer, a polymer constituting the reaction
product of alkyl methacrylate, polyethylene glycol methacrylate and
maleic anhydride, and a polymer constituting the reaction product
of alkyl methacrylate, polyethylene glycol methacrylate and imide
of maleic anhydride, and tetraethylene pentamine; the polyglycol
substituted polyesters disclosed in U.S. Pat. No. 3,083,187; and
the polyglycol substituted polyamides disclosed in U.S. Pat. No.
3,083,188. The methods of preparation of these latter dispersants
are detailed in said patents.
The fourth constituent of the first liquid toner is a pigment.
The pigment employed can be any one of the many now known to the
art in connection with liquid electrostatographic developers. As is
well-known, these pigments essentially constitute very fine solid
particles the size of which is in the submicron range, which are
opaque in mass and which are capable of acquiring an electroscopic
charge. They are insoluble in the liquid carrier. So many different
kinds and species of pigments are known that only typical
representative examples will be mentioned. These are: powdered
metals, e.g., powdered aluminum; powdered metal oxides, e.g.,
powdered magnetic iron oxide; powdered metal salts, e.g., powdered
cadmium selenide (CdSe), powdered lead iodide (PbI.sub.2), powdered
lead chromate (PbCrO.sub.4); Cyan Blue GT 55-3295 (American
Cyanamid Company, Pigments Division)* (74160)** described in United
States Letters Patent No. 2,486,351; Cibacron Black BG (Ciba
Company, Inc.); Cibacron Turquoise Blue G (Ciba); Cibalon Black BGL
(Ciba); Orasol Black BRG (Ciba); Orasol Black RBL (Ciba); Acetamine
Blac, CBS (E. I. du Pont de Nemours and Company, Inc.); Crocein
Scarlet N Ex (du Pont) (27290); Fiber Black VF (duPont) (30235);
Luxol Fast Black L (duPont) (Solv. Black 17); Nigrosine Base No.
424 (duPont) (50415 B); Oil Black BG (duPont) (Solv. Black 16);
Rotalin Black RM (duPont); Sevron Brilliant Red 3 B (duPont); Basic
Black DSC (Dye Specialties, Inc.); Hectolene Black (Dye
Specialties); Azosol Brilliant Blue B (General Aniline and Film
Corporation, Dyestuff and Chemical Division) (Solv. Blue 9); Azosol
Brilliant Green BA (General Aniline) (Solv. Green 2); Azosol Fast
Brilliant Red B (General Aniline); Azosol Fast Orange RA Conc.
(General Aniline) (Solv. Orange 20); Azosol Fast Yellow GRA Conc.
(General Aniline) (13900 A); Basic Black KMPA (General Aniline);
Benzofix Black CW-CF (General Aniline) (35435); Cellitazol BNFV Ex
Soluble CF (General Aniline) (Disp. Black 9); Celliton Fast Blue AF
Ex Conc (General Aniline) (Disp. Blue 9); Cyper Black IA (General
Aniline) (Basic Blk. 3); Diamine Black CAP Ex Conc (General
Aniline) (30235); Diamond Black EAN Hi Con. CF (General Aniline)
(15710); Diamond Black PBBA Ex (General Aniline) (16505); Direct
Deep Black EA Ex CF (General Aniline) (30235); Hansa Yellow G
(General Aniline) (11680); Indanthrene Black BBK Powd. (General
Aniline) (59850); Indocarbon CLGS Conc. CF (General Aniline)
(53295); Katigen Deep Black NND Hi Conc. CF (General Aniline)
(53190); Nyliton Black B (General Aniline); Palatine Fast Black
WANA Conc. CF (General Aniline) (15711); Rapidogen Black 3 G
(General Aniline) (Azoic Blk. 4); Sulphon Cyanine Black BA-CF
(General Aniline) (26370); Zambezi Black VD Ex Conc. (General
Aniline) (30015); Azo Oil Black (National Aniline Division of
Allied Chemical and Dye Corporation (Solv. Blk. 12); Iosol Blue 6 G
(National Aniline) (Solv. Blue 30); Spirit Nigrosine SSB (National
Aniline) (50415); Methyl Violet T Lake (N. Y. Color and Chemical
Co.) (42535); Rubanox Red CP-1495 (The Sherwin-Williams Company)
(15630); Victoria Blue Molybdate Lake (Standard Ultramarine and
Color Co.) (42595); Black M Toner (General Aniline) a mixture of
carbon black and black dye precipitated on a lake; Toner 8100 (Paul
Uhlich and Company, Inc.) a mixture of carbon black and black dye
precipitated on a lake; Raven 11 (Columbian Carbon Company) carbon
black aggregates with a particle size of about 25mu, Statex B-12
(Columbian Carbon Co.) a furnace black of 33mu average particle
size and chrome green.
The fifth constituent of the first liquid toner is a charge
director.
The charge directors which are per se well known in the field of
liquid electrostatographic image developers must be soluble or
dispersible in the paraffinic solvent system and must create or
augment an electrostatic charge on the sub-micron pigment
particles. Examples of useable charge directors are:
Aerosol OT which is a di-2-ethylhexyl sodium sulfosuccinate;
Aerosol TR which is di-tridecyl sodium sulfoccinate;
the aluminum, chromium, zinc and calcium salts of
3,5-dialkylsalicylic acid, wherein the alkyl group is propyl,
isopropyl, butyl, isobutyl, tertiary butyl, amyl, isoamyl and other
alkyl groups up to C-18;
the aluminum, chromium, zinc and calcium salts of dialkyl
gamma-resorcylic acid, wherein the alkyl is as above;
the isopropylamine salt of dodecylbenzene sulfonic acid;
aluminum, vanadium and tin dresinates (the metal dresinates are
prepared by adding a solution of the metal sulfate to a solution of
the sodium salt of Dresinate 731 manufactured by Hercules Powder
Co.);
cobalt, iron, lithium, tin and manganese octoates;
OLOA 1200 which is a product of the Oronite Division of California
Chemical Co., the same being a partially imidized polyamine with
lubricating-oil soluble polyisobutylene chains and free secondary
amines, its specifications are: gravity at 60.degree. F. API 22.9,
specific 0.92 flash point by the Cleveland open cup method,
425.degree., viscosity at 210.degree. F., 400 SSU, color (ASTM
D-1500) L55D, nitrogen, percentage by weight 2.0, and alkalinity
value, (SM-205-15) 43;
soya bean lecithin;
an aluminum salt of 50-50 by weight mixture of the mono- and
di-2-ethylhexyl esters of pnosphoric acid;
zinc, lead, copper, cadmium, calcium, aluminum and iron
stearates;
zinc and aluminum palmitates;
aluminum oleate;
copper, manganese, cobalt and lead linoleates;
manganese linoresinate; and
Nalcamine G-14, manufactured by Nalco Chemical Co., this being
1-[2-hydroxyethyl]-2-[mixed pentadecyl and
heptadecyl]-2-imidazoline.
The linoresinates are metal soaps of tall oil.
The various constituents of the first liquid toner are almost
invariably chemically inert to one another at ambient temperatures
and are inert to the various constituents of the second liquid
toner at like temperatures. All of the constituents of the first
liquid toner are selected and admixed solely for their physical
characteristics and generally not for chemical interaction. The
constituents are heat stable under conditions of use and at
temperatures to which they are exposed in transit and in storage.
An electrostatographic developing bath solely constituting the
first liquid toner will not gel under the operating conditions
prevailing in a liquid electrostatographic developing apparatus,
i.e. at a temperature up to as high as 125.degree. F. Moreover,
such heat stability and non-gelling characteristics carry over into
the second liquid developer component of the hybrid liquid
developer of the present invention.
The following are examples of liquid electrostatographic first
toners in concentrated form:
EXAMPLE I ______________________________________ 40 gs. Krumbhaar
484 15 gs. Toner 8100 15 gs. Spirit Nigrosine SSB 5 gs. Raven 11 50
gs. Alkanol DOA 150 mls. Shell Sol 71 2 gs. Manganese linoleate 2
gs. Aluminum stearate ______________________________________
EXAMPLE II ______________________________________ 25 gs. Nevchem
100 9 gs. Toner 8100 9 gs. Spirit Nigrosine SSB 120 gs. Shell Sol
71 0.25 g. Aluminum dresinate 17.5 gs. Alkanol DOA
______________________________________
EXAMPLE III ______________________________________ 55 gs. Resin
NC-11 17.5 gs. Alkanol DOA 182 gs. Shell Sol 71 0.5 g. Aluminum
stearate 28 gs. Cyan Blue GT 55-3295
______________________________________
EXAMPLE IV ______________________________________ 25 gs. Staybelite
20 gs. Alkanol DOA 10 gs. Mineral oil (U.S.P.) 15 gs. Toner 8100 9
gs. Statex B-12 100 gs. Isopar K 1 g. Tin octoate
______________________________________
The mineral oil is employed to slightly increase viscosity and
thereby reduce the settling for insoluble constituents and to
inhibit the tendency of the concentrate to dry out and form a crust
in the feeder valve.
EXAMPLE V ______________________________________ 55 gs. Resin NC-11
17.5 gs. Lube Oil 564 1 g. Aluminum stearate 182 gs. Isopar H 30
gs. Powdered cadmium selenide
______________________________________
EXAMPLE VI ______________________________________ 25 gs. Nevchem
100 20 gs. Alkanol DOA 10 gs. Polymerized castor oil 15 gs. Black M
Toner 9 gs. Statex B-12 100 gs. Isopar K 0.5 g. Cobalt octoate (12%
solution in mineral oil ______________________________________
The polymerized castor oil is used for the same purpose as the
mineral oil.
EXAMPLE VII ______________________________________ 25 gs. Foral 85
20 gs. Alkanol DOA 10 gs. Polymerized castor oil 15 gs. Toner 8100
9 gs. Statex B-12 100 gs. Isopar G 0.5 g. Aluminum stearate
______________________________________
EXAMPLE VIII ______________________________________ 25 gs. Nevchem
100 20 gs. Alkanol DOA 10 gs. Polymerized castor oil 15 gs. Toner
8100 9 gs. Statex B-12 100 gs. Isopar K 0.5 g. Cobalt Octoate (12%
solution in mineral oil) ______________________________________
EXAMPLE IX ______________________________________ 25 gs. Staybelite
Resin 20 gs. Alkanol DOA 10 gs. Polymerized castor oil 15 gs. Toner
8100 9 gs. Statex B-12 100 gs. Isopar G 5 drops Aluminum dresinate
(10% solution in Isopar G)
______________________________________
EXAMPLE X ______________________________________ 25 gs. Staybelite
Resin 20 gs. Alkanol DOA 10 gs. Polymerized castor oil 20 gs.
Statex B-12 4 gs. Cyan Blue GT 1 g. Aluminum stearate 100 gs.
Isopar K ______________________________________
Each of the foregoing concentrated liquid electrostatographic
developers is formed by introducing all of the recited ingredients
into a ball mill and milling the same therein at room temperature
or above, e.g. 110.degree. F, for an extended period of time, e.g.
24 hours.
The second liquid toner used in the hybrid toner of the present
invention is described in detail in application Ser. Nos. 810,841
and 7,253, but is redescribed below for the sake of completeness.
The second liquid toner essentially consists of a solvent system,
optionally a coloring agent, and a complex molecule including
plural polymeric moieties of which at least one is solvated by the
solvent system and at least one is non-solvated by the solvent
system, the color agent optionally being in the form of a moiety of
the molecule in the nature of a chromophore. At least one of the
polymeric moieties is of a resinous nature and serves as a
fixative. The nonsolvated polymeric moiety provides a solid
particle in the solvent system (the continuous phase) enabling the
desired size of particles 25 m.mu. and 25.mu.m to be formed and
permitting electrophoretic deposition to take place in the
formation of a patterned deposit on a substrate, e.g., enabling
electrostatic attraction to take place between a particle and a
latent electrostatic image on a copy sheet. The solvated polymeric
moiety functions to maintain the complex molecule in suspension,
that is to say, to prevent settling of the molecule and hence, in
effect, operates as a dispersing agent. Thus, in the complex
molecule, several functions of constituents of conventional (first
type) toners are amalgamated. It should be observed that the
polymeric moiety or moieties which impart the resinous
characteristic to the complex molecule may be either the solvent
solvated polymeric moiety or the solvent non-solvated polymeric
moiety or both. This complex molecule is a so-called "tailored"
molecule, that is to say, it is an artifically created molecule
which in a single compound provides plural functions required in a
toner of the first type the presence of plural chemically separate
constituents. A charge director is an additional most desirable
component of the second liquid toner.
The basic building block of the second liquid toner is the solvent
system. The term "basic building block" is not used in the sense
that the solvent system is the core of the complex molecule which
is employed, but rather that the nature of the solvent system
influences the particular type complex molecule that is to be
employed. Once the solvent system has been chosen, certain
parameters of the second liquid toner developer constituents and
specifically of the complex molecule, are indicated. Any type of
solvent system can be used which is compatible with the first
liquid toner, indeed the two liquid toners are mutually compatible,
and with the particular apparatus and method using any specific
form of a hybrid liquid toner embodying the present invention.
Preferably both the first and the second liquid toners employ the
same solvent system. Both liquid toners of the two toners whose
admixture constitutes the present invention preferably are based
upon a non-polar solvent system such as is conventionally employed
presently in the creation of most patterned deposits and is
currently widely used in electrostatographic toners. Nevertheless,
the second liquid toner is not limited to a non-polar solvent
system and can be equally well employed with a polar solvent
system, where such a system is practical in any specific apparatus
or method that can make use of such a toner and where the first
liquid toner uses the same or a compatible solvent system. Because
the present large-scale commercial use of liquid toners is with
apparatuses and methods that utilize non-polar solvents, the
following description of the second liquid as to the particular
examples and compositions stresses a non-polar continuous phase,
i.e., solvent system. Such a non-polar solvent system includes an
organic non-polar liquid having the characteristics of those
previously mentioned above and referred to in particular under
subdivisions (a)-(h) above which are incorporated here by
reference. Examples of such solvent systems are identical to those
described with respect to the solvent systems of the first liquid
toner and, indeed, it is preferred to use identical solvent systems
for both the first and the second liquid toners so that the hybrid
toner utilizes a single solvent system.
The second liquid toner uses with the solvent system a complex
molecule having the polymeric moieties mentioned above. Hence, the
second liquid toner is basically a latex toner, which is to say, a
toner that looks like a natural latex in that it constitutes a
liquid continuous phase having the desired attributes for use in a
patterned deposition system, together with a dispersed phase which
is an amphipathic polymer. The term "latex" as used herein refers
to a colloidal suspension of a synthetic polymer in any liquid, for
instance, as prepared by emulsion or suspension polymerization. An
"amphipathic" substance is one that has an affinity for two
different materials, for instance, oil or water, or two different
phases, so that one polymeric moiety of the amphipathic polymer,
which is the foregoing complex molecule, will be solvated by the
phase for which it has an affinity, which, in this instance, is the
solvent system, and another polymeric moiety will not be solvated
by this same phase, that is to say, will be insoluble in this
phase, so that the phenomenon is created when the amphipathic
polymer is contained in the solvent system of at least one
polymeric moiety of the polymer being solvated by the solvent
system and at least one polymeric moiety being non-solvated by the
solvent system. The amphipathic polymer combines in one complex
molecule the fixing agent, which is one or more of the polymeric
moieties, the dispersing agent, which is one or more of the
polymeric moieties, and optionally, a color agent, which is one or
more of the polymeric moieties. This complex molecule, i.e.,
amphipathic polymer, by virtue of the fact that it is a molecule
rather than a composition including a mixture of pigment particles,
creates a narrow range of size distribution of the non-solvated
particles which ultimately are deposited on a substrate, e.g., a
copy sheet, as by electrostatographic development, to create a
patterned deposition. Desirably the particle size distribution of
the non-solvated particles in the second liquid toner is within two
orders of magnitude and preferably is within about one order of
magnitude. The foregoing ranges are what is denoted by the term
"mono-dispersed".
The second liquid toner is created generally as follows: Firstly,
the solvent system for the second toner is chosen, for example, a
non-polar solvent such as a petroleum fraction like the ones
mentioned above, although as previously observed, other solvents
could be used, e.g. polar solvents such as water.
It is appropriate to reiterate at this point that patterned
depositions utilizing electrostatic phenomena, e.g.,
electrophoresis, do not necessarily involve the use of non-polar
solvent systems for either of the first and the second liquid
toners. Thus an electrostatic method using water as the carrier
system in electrostatography is shown in U.S. Pat. No. 3,425,829,
issued Feb. 4, 1969. Other suitable solvent systems, by way of
example, i.e., solvent systems other than petroleum fractions and
water, include alcohols, e.g., those having 1 to 6 carbon atoms,
such as ethylene glycol; ethers, including ethyl isobutyl ether,
methyl isopropyl ether, the (C.sub.1 -C.sub.4) alkyl mono ethers of
ethylene glycol, and dioxane; ketones, including acetone, methyl
ethyl ketone, methyl isopropyl ketone, and ethyl isobutyl ketones;
esters, including ethyl acetate, amyl acetate, butyl propionate,
and the acetates of the mono- (C.sub.1 -C.sub.4)- alkyl ethers of
ethylene glycol; and halogenated hydrocarbons, such as chloroform,
ethylene dichloride, monochloro benzene and certain Freons.
After selection of the solvent system a polymeric backbone molecule
is chosen for the second liquid toner, which is solvated by the
selected solvent system, i.e, which is fully soluble to the limit
of its solubility. Next a graft or block polymerization or
copolymerization is carried out in such a manner, hereinafter
described, that non-solvated polymeric chains, which is to say,
polymeric chains which are not solvated by the chosen solvent
system, are created in the solvent system and are chemically joined
with, i.e., to, the solvated polymeric backbone molecule. The
mechanism by which the chains are created and chemically joined is
not of critical importance. For example, the chains first can be
formed and then grafted onto the polymeric backbone molecule or a
molecule of a grafting monomer can be first reacted with the
polymeric backbone molecule and subsequently this first monomer can
be polymerized with the other grafting monomers present in the
solvent system.
The non-solvated polymeric moiety, i.e., fraction or chains,
originates as a monomer which usually and preferably is solvated by
the solvent system for convenience in carrying out the reaction and
to minimize the time required for the reaction and also to
eliminate the need for solubilizers or multi-solvent systems in the
second liquid toner. However, as the reaction for the formation of
the chains proceeds, the addition to the backbone polymer, which is
to say, the newly formed chains, become progressively non-solvated
and eventually becomes a non-solvated polymeric moiety (portion)
which constitutes a dispersed phase, this, despite the fact that
the polymeric backbone still is solvated by the solvent system. It
is interesting to observe that the reaction as it takes place
initially causes a transformation of the clear solution of the
solvated backbone polymer and of the solvated monomer first into a
slightly hazy stage and then becomes more turbid as the minutes
pass until ultimately a latex is formed.
It is also possible to use a reverse process in which a
non-solvated polymeric backbone is partially solvated by graft or
block polymerization.
As mentioned previously, the largest present-day commercial use for
liquid toners is in electrostatography such as is used in the
so-called "liquid" xerographic copying machines. The solvent system
used in liquid toners for such purpose is usually a petroleum
fraction such as described heretofore with respect to the first
liquid toner and, hence, in detailing various process steps in the
manufacture of the complex molecule this particular solvent system
will be employed, although it is understood that the second liquid
toners can employ any solvent system whatsoever.
Assuming, then, that the solvent system for the second liquid toner
is a petroleum fraction, a polymeric backbone material is selected
which is solvated by such petroleum fraction. A popularly employed
petroleum fraction is odorless mineral spirits (hereinafter OMS).
There are many polymeric materials which are solvated by OMS. These
include, e.g., polymeric materials derived from natural sources
such as crepe rubber; refined oxidized linseed oil and degraded
rubber, and synthetic polymers such as alkyd resins;
polyisobutylene; polybutadiene; polyisoprene; polyisobornyl
methacrylate; acrylic polymers of long chain esters of acrylic or
methacrylic acid such as stearyl, lauryl, isodecyl, octyl,
2-ethylhexyl and hexyl; butyl esters of acrylic or methacrylic
acids; polymeric vinyl esters of long chain acids such as vinyl
stearate, vinyl laurate, vinyl palmitate and vinyl myristate;
polymeric vinyl alkyl ethers, including poly (vinyl ethyl ether)
sold under the trademark Bakelite EDBM by Union Carbide Corp., poly
(vinyl isopropyl ether), poly (vinyl isobutyl ether) and poly
(vinyl n-butyl ether). As can be seen from the examples given, the
polymers chosen have a structure similar to that of the solvent
which is going to solvate them, i.e., the polymers and the solvent
system have a similar degree of polarity. As long as this similar
polarity is maintained, copolymers, e.g., lauryl methacrylate-butyl
acrylate, t-octyl methacrylate-butyl methacrylate, lauryl
methacrylate-glycidyl methacrylate, 2-ethyl hexyl acrylate-acrylic
acid, isodecyl methacrylate-diethylaminoethyl methacrylate and
vinyl toluene-butadiene; terpolymers, e.g., lauryl
methacrylate-isodecyl methacrylatemethyl methacrylate, stearyl
methacrylate-cyclohexyl acrylatemethacrylic acid, octyl
acrylate-crotonic acid-dodecyl methacrylate, glycidyl
methacrylate-stearyl methacrylate-lauryl methacrylate, lauryl
methacrylate-octyl methacrylate-glycidyl methacrylate and isodecyl
methacrylate-stearyl methacrylate-acrylic acid; and tetrapolymers,
e.g., N-vinyl pyrrolidone-butyl acrylate-lauryl
methacrylate-stearyl methacrylate and acrylic acid-stearyl
acrylate-methyl methacrylate-isodecyl acrylate, may be used, as
well as block and graft copolymers, block and graft terpolymers,
block and graft tetrapolymers and multi-type monomer/polymers in
general as the backbone structure.
If desired, the backbone structure with or without added chains can
be created in a solvent other than that in which it is ultimately
to be used, i.e., in a solvent other than the solvent system of the
second liquid toner. The original solvent in which the backbone
structure with or without added chains is created can either be
extracted or it can be part of a multi-solvent system in the second
liquid toner. Many monomers which it might be desirable to employ
in building a backbone structure are not sufficiently solvated by
OMS or other solvent system of the second liquid toner to enable
the polymerization of the desired structure to be effected in OMS.
In such a case, a copolymerization utilizing such insufficiently
solvated monomers may be carried out in a solvent of higher K.B.
number with another monomer which is solvated by OMS, as long as
the resultant copolymer contains enough of the second monomer so
that the backbone can be solvated by OMS. Such a copolymerization,
for example, could be carried out in benzene, the resulting
copolymer precipitated by the addition of methanol, freed from
solvent, and dissolved in OMS to function as the backbone during
the subsequent graft or block polymerization or graft or block
copolymerization.
The discussion above of synthetic polymeric materials suitable for
use as the backbone, also often hereinafter sometimes referred to
as the "precursor", in an OMS-based electrostatographic toner
system is not limited to addition polymers; synthetic condensation
polymers can also serve as the backbone or precursor in this system
as long as they can be solvated by the chosen solvent medium, e.g.,
the self-condensation polymer of 12-hydroxystearic acid.
Inasmuch as the second liquid toner is not limited to the use of
any particular solvent system, there is no limitation on the
monomers that can be used to fabricate the polymeric constituents
of such system. In the particular system being discussed, however,
that based on OMS, the following list of backbone polymers is
exemplificative but not exclusive:
(a) the homopolymers of the C.sub.4 -C.sub.22 esters of acrylic and
methacrylic acid, such as polyhexyl methacrylate and acrylate,
polyisodecyl methacrylate and acrylate, polylauryl methacrylate and
acrylate, polytetradecyl methacrylate and acrylate, and polystearyl
methacrylate and acrylate, all in the molecular weight range of
about 10.sup.3 to about 10.sup.6, but preferably not smaller than
10.sup.4 ;
(b) copolymers, with each other, of any of the above monomers used
to form the homopolymers under (a), and also with the methyl,
ethyl, isopropyl and propyl esters of acrylic and methacrylic acid,
provided that the ratios of non-solvated to solvated monomers are
kept in a proportion such as to insure solvation of the resulting
copolymer by OMS;
(c) copolymers of the above mentioned methacrylic and acrylic acid
esters with monomers containing other functional groups as, for
example, acrylic acid, methacrylic acid, crotonic acid, maleic
acid, atropic acid, fumaric acid, itaconic acid, citraconic acid,
acrylic anhydride, methacrylic anhydride, maleic anhydride,
acryloyl chloride, methacryloyl chloride, acrylonitrile,
methacrylonitrile, acrylamide and derivatives thereof,
methacrylamide and derivatives thereof, hydroxyethyl methacrylate
and acrylate, hydroxypropyl methacrylate and acrylate,
dimethylaminomethyl methacrylate and acrylate, dimethylaminoethyl
methacrylate and acrylate, diethylaminomethyl methacrylate and
acrylate, diethylaminoethyl methacrylate and acrylate,
t-butylaminoethyl methacrylate and acrylate, allyl alcohol and
derivatives thereof, cinnamic acid and derivatives thereof, styrene
and derivatives thereof, methallyl alcohol and derivatives thereof,
propargyl alcohol and derivatives thereof, indene and derivatives
thereof, norbornene and derivatives thereof, vinyl ethers, vinyl
esters and other vinyl derivatives, glycidyl methacrylate and
acrylate, mono- and dimethyl maleate, mono- and diethyl maleate,
mono-n-butyl maleate, mono-sec-butyl maleate, mono-ter-butyl
maleate, monobenzyl maleate, mono-2-ethylhexyl maleate,
mono-n-octyl maleate, mono- and dimethyl fumarate and mono- and
diethyl fumarate;
(d) homopolymers of olefins such as butadiene, isoprene and
isobutylene, and copolymers of these monomers with any of the
monomers listed above consistent with the solvation limitation as
described under (b);
(e) terpolymers and tetrapolymers of the above;
(f) polycarbonates, polyamides, polyurethanes and epoxies.
With the backbone, i.e., precursor, chosen, there are added on to
this backbone polymeric chains of a different degree of polarity
from that of the solvent so that these chains although grafted on
or block polymerized to the solvated backbone, will themselves be
non-solvated by the solvent system and, hence, form a dispersed
phase. This addition of such chains is carried out via either a
block or graft polymerization as just noted. Suitable monomers
which form polymers that are too polar to be solvated by the OMS
solvent medium are vinyl acetate, methyl acrylate and methacrylate,
ethyl acrylate and methacrylate, propyl acrylate and methacrylate,
isopropyl acrylate and methacrylate, hydroxy ethyl acrylate and
methacrylate, hydroxy propyl acrylate and methacrylate,
acrylonitrile, methacrylonitrile, acrylamide, methacrylamide,
acrylic acid and anhydride, methacrylic acid and anhydride, mono
methyl maleate, mono ethyl maleate, mono-n-butyl maleate,
mono-sec-butyl maleate, mono-ter-butyl maleate, monobenzyl maleate,
mono-2ethylhexyl maleate, mono-n-octyl maleate, mono methyl
fumarate, mono ethyl fumarate, styrene, vinyl toluene, maleic acid
and anhydride and crotonic acid and its anhydride. The invention is
not limited to homopolymers in this further polymerization
procedure; copolymers and terpolymers or polymers of greater
degrees of complexity, but of the proper polarity, could be joined
to the chosen solvated backbone structure to form the latex.
When a grafting procedure is chosen for the latex forming step, and
there are no ethylenic or other unsaturated bonds available in the
backbone for accepting the graft, polymeric chains can be grafted
onto a saturated backbone, nevertheless, through the use of
activating methods known to those skilled in the art. This method,
however, although useful, leads to a haphazard activation by the
initiator employed of a site or sites in the backbone molecule
which subsequently serve to initiate the polymerization of the
grafting monomer. A preferred method, rather than haphazard
activation, is to construct the backbone molecule of the second
liquid toner in such a way as to produce ethylenically unsaturated
double bonds or other unsaturated bonds containing pendant moieties
to serve as sites to be activated by the initiator for in situ
graft polymerization. Thus, there may be employed an OMS solvated
backbone molecule consisting of a copolymer of stearyl
mathacrylate-glycidyl methacrylate of the proper (27:1) monomer
ratio and molecular weight, e.g., 10,000 to 150,000. Methacrylic
acid can be reacted with this polymer in the presence of a
polymerization inhibitor to provide ethylenically unsaturated
double bond containing sites through an esterification reaction for
activation and subsequent in situ polymerization or
copolymerization. In such a manner, precursors for a graft
polymerization or copolymerization can be made. The term
"precursor" as used herein denotes a backbone such as described, as
well as a treated (activated) backbone, which is to be used as the
base for reaction to form a latex.
Many different reactions can be utilized to introduce these
ethylenically unsaturated double bond containing pendant groups
into the precursor. If the monomer used in the backbone chain is
called Monomer 1 (said monomer is at least one of two monomers
which forms the backbone chain and which is present in a minority
proportion by weight and which includes an unsaturated bond before
copolymerization, said bond having been reacted in the formation of
the copolymer but still contains a reactive group) and the
additional monomer used to form the precursor is called Monomer 2
(the latter monomer is specifically selected to be reactive with
the reactive group of Monomer 1), the following are illustrative
examples:
______________________________________ Monomer 1 Monomer 2
______________________________________ Acrylic acid Methacrylic
acid Glycidyl methacrylate Maleic acid or acrylate -- Fumaric acid
Atropic acid Allylamine Vinyl amine Hydroxyethyl methacrylate and
acrylate Hydroxypropyl methacrylate Acryloyl or methacryloyl and
acrylate chloride -- Acrylamide Methacrylamide Allyl alcohol
Allylamine Vinyl amine Acrylic acid Vinyl pyridines Methacrylic
acid Glycidyl methacrylate Maleic acid -- Vinylamine Crotonic acid
Allylamine Alkyl hydrogen maleates Dialkylaminoalkyl meth- Aryl
hydrogen maleates acrylates and Alkyl hydrogen fumarates acrylates
Allylamine Vinyl isocyanate -- Vinylamine Methacrylyl acetone
Cyanomethylacrylate -- Vinylamine Allylamine Allylamine Vinyl
.beta.-chloroethyl- -- Vinylamine sulphone Allyl alcohol
Hydroxyalkyl methacrylates Glycidyl methacrylate Methacrylic
anhydride Vinylamine Acrylic anhydride -- Allylamine Maleic
anhydride Hydroxyalkyl methacrylates Allyl alcohol N-hydroxymethyl
Vinyl sulphonic acid -- methacrylamides Vinyl phosphoric acid
Alkoxymethyl methacrylamides
______________________________________
The reverse reactions can also be utilized, i.e. Monomer 2 can be
copolymerized into the backbone and subsequently condensed with
Monomer 1 to create the precursor.
With the precursor formed, the latex is prepared by carrying out,
in a liquid system wherein the precursor or additional fraction
(polymeric moiety) is fully solvated and the other fraction
(polymeric moiety) not fully solvated, the polymerization of the
monomer or comonomers chosen for the additional fraction which
preferably is the dispersed phase in the presence of and in
conjunction with the precursor. In the preferred form of the second
liquid toner, the monomer or monomers chosen polymerize to a
material which is nonsolvated by the solvent system employed in the
second liquid toner. For example, in an OMS-based system using the
stearyl methacrylate-glycidyl methacrylate-methacrylic acid
precursor, typical useful monomers for the additional fraction
include methyl methacrylate, methyl acrylate, ethyl methacrylate,
ethyl acrylate, isopropyl methacrylate, styrene, vinyl acetate,
vinyl chloride, vinyl toluene, acrylonitrile and methacrylonitrile,
as homopolymers or copolymers, or any one or more of the above with
maleic anhydride, crotonic acid, acrylic acid, mono methyl maleate,
mono ethyl maleate, mono-n-butyl maleate, mono-sec-butyl maleate,
mono-ter-butyl maleate, monobenzyl maleate, mono-2-ethylhexyl
maleate, mono-n-octyl maleate, mono methyl fumarate, mono ethyl
fumarate, methacrylic acid, dimethylaminomethyl methacrylate, or
terpolymers or tetrapolymers of any of the foregoing. When this
polymerization is carried out, part of the monomer polymerizes with
the precursor molecule (solvated backbone) to form a graft
copolymer which is one form of complex tailored molecule for the
second liquid toner, and this serves to stabilize any disperse
polymer particles which are not grafted.
It will be appreciated that the dispersed phase which, in
principle, is the non-solvated moiety of the complex amphipathic
resin molecule, also may include dispersed non-grafted nonsolvated
polymer particles. Although the latter are not particularly
desirable by virtue of their non-solvation, they are aggregatable
and, moreover, are able to behave electrophoretically so that they
are capable of being selectively attracted to differentially
electrostatically charged areas, whereby to form a graphic
representation by electrostatography.
With a latex of the foregoing character constituting the complex
tailored amphipathic resin molecule as thus far described, the
fixative (substrate bonding) and dispersant functions are combined
into a single molecule which will behave properly in an
electrostatographic system. That is to say, this molecule, of which
there are a great number in any particular second liquid toner,
will be capable of charge direction and fixation and yet will not,
because of the solvated moiety, tend to settle so that it has a
"built-in" dispersing ability.
This complex tailored molecule, together with the solvent system,
is capable, by itself, in conjunction with a charge director, of
use as a second liquid toner because it need not form a visible
selective deposition on a differentially electrostatically charged
substrate, e.g. when used to deposit an image that will be used as
a lithographic master. However, it is additionally desirable for
the second liquid toner to contain a color ranging from black to
white through all of the various hues. Phrased differently, it is
desirable to color the suspended latex particles to that when they
are preferentially attracted to differentially electrostatically
charged regions of a substrate and deposited thereon, the films
left by the deposit ("film" is here used in a sense not of a broad
continuous layer but, rather, of a coating which may cover only a
physically small portion of an area and may have any type of
peripheral configuration depending upon the image that is to be
produced) will likewise be colored so that they can be readily
visible and also, if desired, so that a specific color can be
created.
One way of imparting the color is by using either pigments or dyes
added to the latex and physically dispersing them therein as by
ball milling or high shear mixing.
The pigment employed in the second liquid toner can be any one of
the many now known to the art in connection with liquid
electrostatographic developers. As is well known, these pigments
essentially constitute very fine solid particles the size of which
is in the submicron range and which are opaque en masse. They are
insoluble in the liquid system. Typical pigments are those listed
hereinabove with respect to the first liquid toner.
When the dispersed phase is colored by pigment, such preferably are
non-reactive with the amphipathic polymer of the second toner and
with the constituents of the first liquid toner. It is believed
that pigment particles are held to the non-solvated latex polymeric
moiety by second order forces only, i.e., are thus held to the
dispersed phase of the complex amphipathic resin molecule.
In another form of the second liquid toner pigments or dyes are
employed which are chemically bonded to the latex, that is to say,
which become chemically bonded to and are part of the complex
molecule. The chemical bonding can be to the precursor before the
graft or block polymerization of the added chains or it can be to
the chains added by graft or block polymerization.
As to the dyes, as distinguished from pigments, these may be used
to color the specific complex amphipathic resin polymer molecule of
the second liquid toner and specifically to color the dispersed
non-solvated phase thereof by being held thereto by second order or
surface adsorption forces or the dyes can be chemically reacted
with the complex tailored molecule, either after its formation, or
to the precursor, or to the chain as it is being or after it has
been grafted or block polymerized.
The dyes are incorporated in the second liquid toner by second
order or surface adsorption forces, as by heating the latex and dye
together for a sufficient time, for example, one to twelve hours.
One type of example of such dyes is disperse dyes for dyeing
polyester and copolymers of acrylonitrile and vinyl chloride where
the dispersed phase is a polyester or a copolymer of acrylonitrile
and vinyl chloride. Such dyes include: Latyl Orange 3R (DuPont)
(C.I. Disperse Orange 26); Calcosperse Yellow GL (American
Cyanamid) (C.I. Disperse Yellow 57); Calcosperse Blue B (American
Cyanamid) (C.I. Disperse Blue 77); Foron Blue BGL (Sandoz Inc.)
(C.I. Disperse Blue 73); Latyl Brown MS (DuPont) (C.I. Disperse
Brown 2); and Latyl Violet BN (DuPont) (C.I. Violet 27). Other
examples of such dyes are basic dyes for polyacrylics, where the
dispersed phase is a polyacrylic. Typical of such dyes are: Sevron
Blue BGL (Dupont) (C.I. Basic Violet 15); Deorlene Brilliant Red 3B
(Ciba) (C.I. Basic Red 26); Calcozine Acrylic Blue G (American
Cyanamid) (C.I. Basic Blue 38); Astrazon Yellow Brown GGL
(Farbenfabriken Bayer) (C.I. Basic Orange 30); and Astrazon Red 5BL
(Farbenfabriken Bayer) (C.I. Basic Red 24).
A better approach and one which is preferred in a more
sophisticated form of the second liquid toner is to create a
dispersed (non-solvated) phase of a copolymer containing reactive
groups which will react with reactive groups of a chromophoric
nature, for example, a dispersed phase of a copolymer containing
basic groups which can be reacted with acid dyes. An example of a
dispersed phase of a latex which can be used in the foregoing
manner is a terpolymer of acrylonitrile, 2-methyl-5-vinyl pyridine
and vinyl acetate. Such terpolymer can be reaction dyed with dyes
containing acid groups of which examples are: Pontacyl Brilliant
Blue A (DuPont) (C.I. Acid Blue 7); Calcocid Brilliant Blue FFR
(American Cyanamid) (C.I. Acid Blue 104); Femazo Brown N (General
Aniline) (C.I. Acid Brown 14); Crocein Scarlet N (DuPont) (C.I. Red
73); Oxanal Yellow I (Ciba) (C.I. Acid Yellow 63); and Benzyl Black
4BN (Ciba) (C.I. Black 26A).
Such a complex tailored molecule is tri-functional. It contains not
only the dispersant and fixative functions but also the coloring
functions. Such a second liquid toner has an essentially
mono-dispersed phase, i.e., a small range of variation of particle
size.
An alternate method of creating the more sophisticated complex
tri-functional amphipathic resin molecule which embodies the
aforesaid three functions of fixing, dispersing and coloring is to
create a dispersed phase of a copolymer containing acid groups
which then are reacted with basic dyes (instead of with the
aforesaid acid dyes). An example of a dispersed phase of such a
latex is a copolymer of vinyl acetate-maleic acid. This is dyeable
with dyes containing basic groups of which examples are: Magenta
(C.I. Solvent Red 41, C.I. No. 42510B), Crystal Violet (C.I.
Solvent Violet 9, C.I. No. 42555B), Bismarck Brown (C.I. Solvent
Brown 12, C.I. No. 21010B, Victoria Blue BA (C.I. Solvent Blue 4,
C.I. No. 44045B), Victoria Blue R (C.I. Solvent Blue 6, C.I. No.
44040R), Victoria Blue 4R (C.I. Solvent Blue 2, C.I. No. 43563B),
Copying Black SK (C.I. No. 11975), Janus Green B (C.I. No. 11050),
Auramine O (C.I. Solvent Yellow 34, C.I. No. 41000B), Victoria
Green (C.I. Solvent Green 1, C.I. No. 42000B), and Rhodamine (C.I.
Solvent Red 49, C.I. No. 45170B).
Still another method of creating a tri-functional complex tailored
amphipathic resin molecule for the second liquid toner by virtue of
a chemical reaction for bonding the color agent to the block or
graft modified precursor is to create a dispersed phase of a
copolymer containing electron acceptor groups, for example, maleic
acid or crotonic acid which are Lewis acids and which are then
reacted with color precursors that are well known to the art. An
example of this latter tri-functional sophisticated complex
molecule is a terpolymer of maleic anhydride-vinyl acetate-styrene
(on a solvated backbone) and reacted with a color precursor such
for instance as bis (p-dimethylaminophenyl)-benzotriazyl methane. A
second liquid toner embodying the foregoing complex molecule will,
per se, produce a deep blue colored deposit.
Where the pigment or dye is reacted with the added groups in the
dispersed phase, the amount of pigment employed can fluctuate from
as low as 5% to a theoretical 100% of the calculated stoichiometric
amount in the second liquid toner. Nevertheless, it is preferred to
have the amount of dye or pigment thus incorporated vary between
about 10% and 50% of the stoichiometric amount, with best results
having been obtained at about 25% of the stoichiometric figure.
There is yet another way for coloring latexes of the second liquid
toners. This is to color the precursor itself, which is to say, the
backbone that is the solvated phase rather than to color the
dispersed unsolvated phase. Although there could be used for
coloring the precursor some of the methods recited above to color
the dispersed phase by chemical reaction or by second order bonds
or surface adsorption or even by chemical reactions of color agents
with the precursor, a highly preferred method is to employ a dye
which is copolymerized into the precursor itself, that is to say,
the solvated backbone, before the backbone is grafted or block
polymerized with the non-solvated moieties (chains). An example of
such a process is set forth below (EXAMPLE XVIII) along with many
other examples of methods of manufacturing the complex amphipathic
resin molecule of the second liquid toner.
It should be observed, moreover, that, if desired, both the
dispersed phase and the solvated precursor can be dyed by any of
the manners above discussed in detail.
As thus far described, there has been provided a stable latex which
constitutes practically all of the necessary ingredients of the
second liquid toner, these including the liquid solvent system with
the complex amphipathic resin molecule having solvated and
non-solvated polymeric moieties and which is tri-functional as to
the fixative, dispersant and colorant or includes a separate
(non-reacted) color agent. It still is, nevertheless, extremely
desirable to include in the second liquid toner a charge director
or directors, the same adding greatly to the depth of color
obtained and aiding in contrast. Hence, there preferably is
included in the second liquid toner as a constituent over and above
the solvent system, the complex molecule and a separate colorant,
if one is not included as a moiety of the complex molecule, a
charge director in a useful concentration. In electrostatographic
development a charge director present in a suitable concentration
is to all intents and purposes a necessity. The charge director or
directors chosen for the second liquid toners may be any of those
mentioned with respect to the first liquid toner and, indeed, the
same charge director or directors are preferably used for both the
first and the second liquid toners which are mixed to form the
hybrid liquid toner or the present invention.
The amounts of the different non-carrier constituents of the first
and the second liquid toners are capable of extremely wide
variation, indeed, so wide that assigning specific figures thereto
of the extreme ranges which function satisfactorily in the hybrid
toner is largely meaningless. For example, the amounts will vary
with the type of machine, climate, machine speeds, types of paper
and experience of the operator, to mention but a few. Also,
particularly in the case of the coloring material, the amounts will
vary with the intensity of the dye or pigment and the desired
degree of intensity of the image. Generally speaking, moreover, the
amounts of the individual non-carrier constituents will increase or
decrease together, although not in strict proportion. Bearing all
of this in mind and in order to assist workers in the art in the
preparation of hybrid toners embodying the present invention, the
following represent approximately maximum and minimum amounts of
the various non-carrier constituents per liter of the first and
second liquid toners in a working toner bath.
For the fixer of the first liquid toner from about 0.05 g. to about
5.0 gs.
For the dispersant of the first liquid toner from about 0.025 g. to
about 5.0 gs.
For the pigment of the first liquid toner from about 0.025 g. to
about 5.0 gs.
For the charge director of the first liquid toner from about 0.0005
g. to about 0.5 g.
For the complex amphipathic molecule of the second liquid toner
where the same includes a dye or pigment either chemically reacted
therewith or bonded thereto or affiliated therewith by surface
adsorption forces from about 0.03 g. to about 30 g.
For the complex amphipathic molecule of the second liquid toner
where the same does not include a color agent reacted or associated
therewith from about 0.03 g. to about 30 g.
For the color agent of the second liquid toner where the same is
not reacted or bound to the complex amphipathic molecule from about
0.03 g. to about 30 g.
For the charge director of the second liquid toner from about 1
.times. 10.sup..sup.-6 g. to about 10 g.
The balance of each toner constitutes the liquid carrier.
Examples of different specific embodiments of the second liquid
toners follow:
The first nine examples are examples of precursors, i.e. examples
of the formation of the backbone, that is to say, the spine, of the
amphipathic molecule with which a subsequent reaction will later be
described in further examples which deal with the formation of the
latices from the precursors and toners from the latices.
EXAMPLE XI
In a clean dry 8 oz. glass jar is placed 100 gs. of
2-ethylhexyl-acrylate and 1 g. of AZBN (azobisisobutyronitrile), a
polymerization initiator. The jar is placed in a water bath
maintained at 75.degree..+-.2.degree. C. After about 30 minutes an
exothermic polymerization takes place. The temperature reaches a
maximum of 120.degree. C. in about 5 minutes after the start of the
exotherm. After it cools down to 90.degree. C. the jar is removed
from the water bath, loosely covered and placed in a hot air oven
at 90.degree. C. overnight to complete the polymerization. The
product is a nearly waterwhite heavy syrup.
EXAMPLE XII
Four hundred grams of petroleum ether (b.p.90.degree. -120.degree.
C) is placed in a 1 liter reaction flask equipped with a stirrer, a
thermometer, a reflux condenser, and a dropping funnel and heated
to a gentle reflux at atmospheric pressure. A solution of 1.2 g.
AZBN in 200 g. of 2-ethylhexyl-acrylate and 6 g. of glycidyl
methacrylate is placed in the dropping funnel and allowed to drip
into the reflux stream at such a rate that the addition takes 3
hrs. The mixture is refluxed at atmospheric pressure for an
additional 2 hrs. at which time 4 g. of acrylic acid, 0.14 g. of 2,
6-di-tertiary butylphenol and 1 g. of lauryl dimethyl amine is
added. The mixture is refluxed at atmospheric pressure for 12 more
hours under a nitrogen blanket to esterify ca. 25% of the glycidyl
rings of the copolymer. The product is a straw-colored somewhat
viscous liquid.
EXAMPLE XIII
In a 500 ml. resin reactor equipped with a stirrer, a thermometer,
a reflux condenser and a dropping funnel is placed 250 gms. of
Isopar E. The solvent is heated to 93.degree..+-.1.degree. C. and
250 gs. of 2-ethylhexyl acrylate containing 1.5 gs. of AZBN is
added dropwise to the hot solvent over a period of 3 hrs. The
mixture is maintained at 93.degree. .+-. 1.degree. C. for 3
additional hours to complete polymerization. All reactions take
place in the reactor at atmospheric pressure. The product is a
slightly viscous strawcolored liquid.
EXAMPLE XIV
In a 1 liter reaction flask equipped with a stirrer, a thermometer
and a reflux condenser is placed 400 gs. of petroleum ether
(b.p.90.degree.-120.degree. C.) and the same is then heated at
atmospheric pressure to a moderate rate of reflux. A solution is
made of 194 gs. lauryl methacrylate, 6.0 gs. of glycidyl
methacrylate and 3.0 gs. of benzoyl peroxide paste (60% by wt. in
dioctyl phthalate) and placed in a 250 ml. dropping funnel attached
to the reflux condenser. The monomer mixture is allowed to drip
into the refluxing solvent at such a rate that it requires 3 hrs.
for the total amount to be added. After refluxing 40 minutes at
atmospheric pressure beyond the final addition of monomer, 0.5 gs.
of lauryl dimethyl amine is added and the refluxing is continued at
atmospheric pressure for another hour. Then 0.1 g. hydroquinone and
3.0 gs. methacrylic acid are added and refluxing continued under a
nitrogen blanket until ca. 52% esterification of the glycidyl
groups is effected (about 16 hours). The resulting product is a
slightly viscous straw-colored liquid.
EXAMPLE XV
EXAMPLE XIV is repeated except that final refluxing is concluded
when ca. 25% esterification of the glycidyl groups has been
effected.
EXAMPLE XVI
In a 5 liter jacketed glass reactor open to the atmosphere and
equipped with a stirrer, a thermometer, a nitrogen bubbler and a
reflux condenser is placed 2400 gs. of Isopar G. The solvent is
heated to 110.degree. .+-. 1.degree. C. by circulating hot
triethylene glycol through the jacket. The temperature of the
glycol is controlled by a proportional heating unit with its
temperature sensor in a reservoir of the heating fluid from which
the hot liquid is pumped to the reactor and subsequently returned
to the reservoir for further heating. A three-way valve arrangement
allows the glycol heating system to be isolated from the jacketed
reactor so that cold water can be immediately supplied to the
jacketed reactor to keep the temperature constant during the
polymerization exotherm when necessary. When the solvent reaches
the forgoing temperature, a mixture of 1035.7 gs. isodecyl
methacrylate, 36.0 gs. glycidyl methacrylate and 18.0 gs. Luperco
ANS-50 (a paste consisting of 50% benzoyl peroxide by weight in
dioctyl phthalate) is added at a constant rate over a 3 hr. period
through a dropping funnel attached to the condenser. After all of
the monomer solution has been added, the reaction mixture is held
at 110.degree. .+-. 1.degree. C. for another 30 min. Then 3.0 gs.
lauryl dimethyl amine is added and the reaction mixture again held
at said temperture for 1 hr. At this point 0.6 gs. hydroquinone is
added and the nitrogen bubbler is started to provide a nitrogen
blanket during the esterification. Then 18.0 gs. of methacrylic
acid is added and the reaction temperature is maintained until an
acid drop indicates that 25% of the glycidyl rings have been
esterified (ca. 8 hrs.). The product that results is a slightly
viscous straw-colored liquid.
EXAMPLE XVII
Using the same apparatus as described in EXAMPLE XVI, 1440 gs. of
Isopar G is warmed to 110.degree. .+-. 1.degree. C. To this hot
solvent, a solution of 1278.6 gs. stearyl methacrylate, 32.4 gs.
glycidyl methacrylate, and 16.2 gs. Luperco ANS 50 in 720 gs. of
Isopar G is added through a dropping funnel attached to the
condenser over a 3 hr. period, the temperature being maintained at
110.degree. .+-. 1.degree.0 C. After all of the monomer solution
has been added, the reaction mixture is held at 110.degree. .+-.
1.degree. C. for another 40 mins. Then 2.8 gs. lauryl dimethyl
amine is added and the reaction mixture again held at said
temperature for 1 hour. At this point 0.54 gs. hydroquinone is
added and the nitrogen bubbler is started to provide a nitrogen
blanket during the esterification. Then 16.2 gs. methacrylic acid
is added and the reaction temperature is maintained until an acid
drop indicates that 24% of the glycidyl rings have been esterified
(ca. 7 hrs.). The product is a slightly viscous straw-colored
liquid.
EXAMPLE XVIII
In a 500 ml. 3-neck round-bottom reaction flask open to the
atmosphere and equipped with a stirrer, a thermometer, a
thermocouple for a thermoregulator and a reflux condenser, is
placed 197.8 g. Isopar G. The solvent is warmed to 110.degree. .+-.
1.degree. C. with stirring. A mixture of 96.0 g. lauryl
methacrylate, 3.0 g. glycidyl methacrylate, 0.74 gs. benzoyl
peroxide (99%), 50 mls. of benzene and 5.0 gs. of
p-phenylazoacrylanilide is prepared by stirring on a magnetic mixer
for 30 minutes at room temperature. Most by not all of the
p-phenylazoacrylanilide dissolves. This mixture is added in 5 ml.
increments at 5 min. intervals over a period of 3 hrs. to the
solvent in the flask. The mixture is kept well stirred so that each
addition will be identical in composition. After the last addition,
the mixture is allowed to react at 110.degree. .+-. 1.degree. C.
for 45 minutes and then 0.25 gs. lauryl dimethyl amine is added.
After one more hour of reaction time, 0.05 g. hydroquinone is added
and a nitrogen sparge is started. Then 1.49 g. methacrylic acid is
added and the temperature of the reaction mixture is maintained at
110.degree. .+-. 1.degree. C. until the drop in acid value
indicates that 25% of the glycidyl rings have been esterified (ca.
6 hrs.). The batch is cooled to 50.degree. C. and added slowly to
2700 mls. of methyl alcohol with continuous vigorous agitation. The
precipitated polymer is allowed to settle for 24 hours and is
recovered by decantation. The polymer is air-dried at room
temperature for 48 hours and then for 4 hours at 50.degree. C. This
polymer is then dissolved in 300 gs. of Isopar G giving a deep
clear orange solution to be used in latex production.
EXAMPLE XIX
In a 500 ml. resin reactor equipped with a stirrer, a thermometer,
a reflux condenser open to the atomosphere, a nitrogen bubbler and
a dropping funnel is placed 197.8 gs. Isopar K and warmed to
110.degree. .+-. 1.degree. C. A mixture of 86.0 gs. lauryl
methacrylate, 9.9 gs. N-1, 1, 3, 3-tetramethyl butyl
methacrylamide, 2.97 gs. glycidyl methacrylate and 0.74 gs. benzoyl
peroxide is placed in the dropping funnel and added to the hot
solvent at a constant rate over a 3 hr. period, the temperature
being maintained at 110.degree. .+-. 1.degree. C. The
polymerization is allowed to continue for 6 more hours after the
last of the monomer mixture has been added (a sample of the mixture
analyzed to this time reveals a 96.4% polymerization). Then 0.12
gs. lauryl dimethyl amine is added to the mixture and it is heated
for another hour at which time 0.05 g. hydroquinone is added and a
nitrogen sparge begins. Next 1.49 gs. methacrylic acid is added and
the temperature of the mixture maintained at 110.degree. .+-.
1.degree. C until a check of the acid content indicates that 25% of
the glycidyl rings have been esterified (ca. 9 hrs.). The product
is a somewhat viscous, straw-colored liquid.
LATICES
The following are examples of latices for the second liquid toner
employing those of the foregoing precursors which yield better
results.
EXAMPLE XX
In a 500 ml. resin reactor open to the atmosphere, and equipped
with a stirrer, a thermometer and a reflux condensor, is placed 360
g. Isopar K, 185 gs. vinyl acetate, 30 gs. of the precursor
prepared according to EXAMPLE XIV, 15 gs. methyl hydrogen maleate
and 4 gs. AZBN. The temperature of the reaction mixture is raised
to 85.degree..+-.2.degree. C. and held there for 4 hours. An
additional 2 gs. of AZBN is then added to the mixture and the
polymerization is carried out for another 4 hours at 85.degree.
.+-. 2.degree. C. A thin blue white latex is obtained with a
particle size of 0.04 to 0.2 microns.
EXAMPLE XXI
A mixture of 27.5 gs. of the precursor solution prepared according
to EXAMPLE XV, 30 g. methyl methacrylate, 0.5 g. methacrylic acid
and 0.4 g. AZBN is charged along with 134 g. petroleum ether (b.p.
60.degree.-90.degree. C.) and 29.5 g. Isopar G into a 500 ml. resin
reactor open to the atmosphere and is gently refluxed for 20
minutes. Then 1.4 g. of a 10% solution by weight of n-octyl
mercaptan in Isopar K is added to the reactor. A mixture of 166. g.
methyl methacrylate, 3.4 g. methacrylic acid, 3.0 g. of the 10%
solution of n-octyl mercaptan in Isopar K, and 0.4 g. AZBN is
dripped at a constant rate into the stream of the gently refluxing
condnesor over a period of 21/2 hours. Gentle reflux is continued
for another 1/2 hour and the batch is then cooled to room
temperature. The resulting product is a smooth, white, slightly
viscous latex with a particle size of 0.4-1.0 microns.
EXAMPLE XXII
In a 2 liter 3-neck round-bottom flask open to the atmosphere and
equipped with a stirrer, a thermometer, and a reflux condenser is
placed 848.5g. Isopar K, 70.7 g. of the precursor solution prepared
according to EXAMPLE XVIII, 471.4 gs. vinyl acetate and 9.4 g.
AZBN. The reaction mixture is heated with constant agitation to
86.degree. C. and the temperature is maintained for 4 hours. The
resulting product is a light lemon yellow latex with a particle
size less than 0.2 micron and a solids content of 31.7%.
EXAMPLE XXIII
A mixture of 18 g. of the precursor solution prepared according to
EXAMPLE XV, 110 g. hydroxypropyl methacrylate, 3 g. AZBN and 200 g.
Isopar K is placed into a 500 ml. resin reactor open to the
atmosphere and heated with constant agitation. The exotherm begins
at 78.degree.-80.degree. C. and the temperature rises to a maximum
of 120.degree. C. and then drops back to 80.degree. C.
Polymerization is complete in 30 minutes. A slight amount of
over-size large particle material is removed by pouring the mixture
through a 200 mesh nylon screen. A white latex of 0.5 micron
particle size is obtained. EXAMPLE XXIV
A solution of 15 g. of Bakelite Union Carbide poly (vinyl ethyl
ether) (vinylite EDBM, a poly(vinyl) ethyl ether) with a reduced
viscosity of 4.0.+-. 0.5 as determined by using 0.1 g. polymer in
100 mls. benzene at 20.degree. C., sp.gr. 0.968 at 20.degree. C.)
in 285 g. of Isopar G is made in a 500 ml. resin reactor open to
the atmosphere through a reflux condenser by shaving the resin into
small particles and agitating it in the solvent at 90.degree. C.
for 20 hours. The solution is cooled to room temperature and 185 g.
vinyl acetate and 2.0 g. benzoyl peroxide (99%) is added. The batch
is heated until reflux occurs (ca. 95.degree. C.) and the
temperature is maintained for 4 hours. After 45 minutes of heating
at said temperature, the solution becomes turbid. After 1 hr. 15
mins. of heating at said temperature the batch becomes so viscous
that although the stirrer continues to run, no agitation is visible
and the product appears to be a thick white cream. After 2 hours of
heating at said temperature the batch begins to thin and at the end
of 3 hours of such continued heating it thins to the consistency of
heavy cream where it remains. At the end of the 4 hours, the
dropwise addition of a solution of 1.5 g. lauroyl peroxide in 30
gs. Isopar G is begun and completed over a 3 hour period while the
temperature of the system in maintained at 95.degree. .+-.
2.degree. C. The mixture is held at this temperature for 3 more
hours after the last of the lauroyl peroxide solution has been
added. The result is a white latex of 0.7-1.5 micron particle
size.
EXAMPLE XXV
A mixture of 180 g. Isopar K, 100 gs. vinyl acetate, 15 gs.
precursor solution prepared according to EXAMPLE XVI, and 2 gs.
AZBN is placed in a 500 ml. reaction flask equipped with a
thermometer, a stirrer, a reflux condenser and an internal cooling
coil. The reacting mixture is heated to and maintained at
86.degree. .+-. 2.degree. C. for 4 hours with continuous agitation.
The flask is open to the atmosphere through the cooled reflux
condenser. Occasionally it is necessary to cool the reacting
mixture by running water through the cooling coil during the early
stages of the reaction. The resulting product is a thin white to
blue-white latex whose particles are too small to be viewed in an
optical microscope. The latex contains 33% solids.
EXAMPLE XXVI
In a 5 liter jacketed glass reactor equipped with a thermometer, a
stirrer, and a reflux condenser (the apparatus of EXAMPLE XVI) is
placed 2160 gs. Isopar K, 180 gs. precursor prepared according to
EXAMPLE XV, 1140 gs. vinyl acetate, 60 gs. N-vinyl-2-pyrrolidone
and 24 gs. AZBN. The reaction mixture is heated to and maintained
at 86.degree. .+-. 2.degree. C. for 4 hours. The resulting product
is a thin white to blue-white latex whose particles are too small
to be viewed in an optical microscope.
EXAMPLE XXVII
In a 500 ml. resin reactor open to the atmosphere and equipped with
a stirrer, a thermometer and a reflux condensor is placed 360 gs.
Isopar K, 190 gs. vinyl acetate, 30 gs. of the precursor prepared
according to EXAMPLE XV, 10 gs. crotonic acid and 4 gs. AZBN. The
temperature of the reaction mixture is raised to 85.degree. .+-.
2.degree. C. and held there for 4 hours. An additional 2 gs. of
AZBN is then added to the mixture and the polymerization is carried
out for another 4 hours at 85.degree. .+-. 2.degree. C. A thin
white latex is obtained
EXAMPLE XXVIII
In a 500 ml. resin reactor open to the atmosphere and equipped with
a stirrer, a thermometer, a thermoregulator, a reflux condenser and
an internal cooling coil is placed 40 gs. Lube Oil Additive 564,
284 gs. Isopar K and 2.2 gs. benzoyl peroxide (99%). With
continuous agitation, the batch is heated to 80.degree. C. and
maintained at that temperature for 2 hours. At this time a mixture
of 10 gs. crotonic acid and 190 gs. vinyl acetate is added all at
once to the reacted precursor which has become a dark amber. When
the temperature of the reaction mixture has returned to 80.degree.
C., AZBN is added to the mixture in 0.5 g. increments at 10 min.
intervals until a total of 4.6 gs. has been added (3 hrs. 40 min.).
The reaction mixture is maintained at 80.degree..+-.2.degree. C.
for 2 hours after the addition of the AZBN is complete. A white
latex is obtained of 35.7% solids with a particle size <0.3
micron.
EXAMPLE XXIX
An example of a dyeing procedure for a latex in which it is
believed that the dye does not react with the latex (although it is
possible that it may be associated therewith by hydrogen bonding)
is a mixture of 10% by weight Sudan Orange RA (Solvent Yellow 14,
C.I. No. 12055) in Isopar K the same being ball milled for 4 hours.
Twenty gs. of this dispersion is added to 100 gs. of the latex
prepared according to EXAMPLE XXVII and the mixture is heated at
130.degree.-135.degree. F. for 8 hours with constant mechanical
agitation. The mixture is filtered through a 200 mesh nylon cloth
and allowed to cool to room temperature. A golden orange-colored
latex is obtained.
SECOND LIQUID TONERS
The following are typical examples of second liquid toners in
concentrated form employing some of the foregoing latices.
EXAMPLE XXX
One hundred gs. of the latex produced in EXAMPLE XXVIII is placed
in a 500 ml. 3-neck round-bottom open top flask equipped with a
stirrer, a reflux condenser and a thermometer, and 2 gs. of
Victoria Blue Base BA (C.I. No. 44045B) is added to it. The
temperature is raised to 80.degree..+-.5.degree. C. and held there
for 2 hours. The blue latex which results is cooled and filtered
through a 200 mesh nylon cloth to remove residual dye. To this
colored latex there is added 2.5 gs. of a 1% by weight solution of
aluminum 3,5-diisopropylsalicylate in Isopar K to form a toner
concentrate. Four gs. of this dyed latex is diluted with 2000 mls.
Isopar K to form a working toner bath. This latex is a complex
molecule including in addition to the solvated and non-solvated
polymeric moieties (in the liquid solvent system) a color agent
moiety. The charge director is a separate compound. When used by
itself as a toner bath in a Dennison Standard Book Copier, blue
prints are obtained.
EXAMPLE XXXI
To the batch of latex as prepared in EXAMPLE XXVII is added 13.65
gs. Victoria Blue Base BA and the temperature of the mixture is
maintained at 85.degree..+-.2.degree. C. for 3 hours. The dark blue
latex is filtered through a 200 mesh nylon cloth and cooled to room
temperature. To this colored latex there is added 25 gs. of a 1%
solution of the aluminum salt of 3,5-di-t-butyl gamma resorcylic
acid in Isopar G to form a toner concentrate. This toner
concentrate likewise represents an example of a color agent moiety
which is part of a complex amphipathic polymeric molecule. Four gs.
of this concentrate is added to 2000 mls. Isopar G to form a
working toner bath. This toner bath in a Dennison Standard Book
Copier, gives intense, bright blue images.
EXAMPLE XXXII
To the batch of latex as prepared in EXAMPLE XX is added 6.8 gs.
Auramine O and 6.8 gs. Rhodamine and the temperature of the mixture
is maintained at 85.degree..+-.2.degree. C. for 3 hours. The now
bright yellow-orange latex is filtered through a 200 mesh nylon
cloth and cooled to room temperature. To this colored latex there
is added 10 gs. of a 1% solution of the aluminum salt of 3,5
di-butyl gamma resorcylic acid in Isopar G to form a toner
concentrate. This toner concentrate likewise represents an example
of a color agent moiety which is part of a complex amphipathic
polymeric molecule. Ten gs. of this concentrate is added to 2000
mls. Isopar G to form a working toner bath. This mixture, when used
by itself as a toner bath in a Scott 3D Copier, gives extremely
bright orange images.
EXAMPLE XXXIII
To the bath of latex as prepared in EXAMPLE XX is added 13.65 gs.
Victoria Green and the temperature of the mixture is maintained at
85.degree..+-.2.degree. C. for 3 hours. The now dark bluish green
latex is filtered through a 200 mesh nylon cloth and cooled to room
temperature. To this colored latex there is added 40 gs. of a 1%
solution of the aluminum salt of 3,5-di-t-butyl gamma resorcylic
acid in Isopar G to form a toner concentrate. This toner
concentrate likewise represents an example of a color agent moiety
which is part of a complex amphipathic polymeric molecule. Four gs.
of this concentrate is added to 2000 mls. Isopar G to form a
working toner bath. This mixture, when used by itself as a toner
bath in a Dennison Standard Book Copier, gives intense, bright
bluish green images.
EXAMPLE XXXIV
Three gs. of the latex prepared according to EXAMPLE XXV are ground
together with 0.25 gs. of Raven 11 in a mortar and pestle, has
added to it 30 drops of a 1% solution of the aluminum salt of
3,5-di-t-butyl gamma resorcylic acid and is thinned with a little
Isopar K to form a toner concentrate. The concentrate is diluted to
a volume of 2000 mls. with Isopar K to form a working toner bath.
When this suspension is used by itself as a toner bath in a
Dennison Standard Book Copier, good black prints are obtained.
EXAMPLE XXXV
To the batch of latex as prepared in EXAMPLE XXVII is added 13.65
gs. Crystal Violet (C.I. No. 42555B) and the temperature of the
reaction mixture is maintained at 85.degree..+-.2.degree.C. for 3
hours. The colored latex is filtered through a 200 mesh nylon cloth
and cooled to room temperature. To this colored latex there is
added 0.05 aluminum dresinate to form a toner concentrate. This
toner concentrate likewise represents an example of a color agent
moiety which is part of the complex amphipathic polymeric molecule.
Three gs. of this latex is added to 2000 mls. Isopar K to form a
working toner bath. This bath, when used by itself in an A-M
Sunbeam 500 Copier, gives very good violet prints.
EXAMPLE XXXVI
To the batch of latex as prepared in EXAMPLE XXVII is added 13.65
gs. Megenta (C.I. No. 42510B) and the temperature of the reaction
mixture is maintained at 85.degree..+-.2.degree. C. for 3 hours.
The colored latex is filtered through a 200 mesh nylon cloth and
cooled to room temperature. To this colored latex there is added
0.05 g. aluminum dresinate and 20 gs. of a 10% solution of Aerosol
OT in Isopar K to form a toner concentrate. This toner concentrate
likewise represents an example of a color agent moiety which is
part of the complex amphipathic polymeric molecule. Three gs. of
this latex is added to 2000 mls. Isopar G to form a working toner
bath. When used by itself as a toner bath in a Dennison Standard
Book Copier, magenta prints are obtained.
EXAMPLE XXXVII
Four gs. of the latex produced according to the EXAMPLE XXIX has
added to it 20 drops of a 1% solution of aluminum diisopropyl
salicylate in Isopar G to form a toner concentrate. Said
concentration when diluted with 2000 mls. Isopar K forms a working
toner bath. This mixture, when used by itself as a toner bath in a
Dennison Standard Book Copier, gives yellowish-orange images.
All but one of the foregoing examples of second liquid toners have
but a single color agent. Optionally, plural color agents may be
used, and it is usually preferred to employ two or more color
agents, the conjoint action of which is to produce a deep color
such, for example, as a brown-black, blue-black or
purple-black.
The preparation of the second liquid toner can be carried out in
still another fashion, although it still involves, of course, the
use of a multi-functional complex polymeric molecule having a
polymeric moiety solvated by and a polymeric moiety unsolvated by
the liquid solvent system; this is to form the amphipathic polymer
polymeric molecule in a solvent in which such molecule is
completely solvated and then by adding another solvent which is a
non-solvent for a polymeric moiety of the polymer but is miscible
with the first solvent, and desolvating this polymeric moiety of
the amphipathic polymer polymeric molecule while said desolvated
polymeric moiety remains bonded to the solvated polymeric moiety of
the polymer, i.e., remains as a part of the polymer. If desired,
all or a part of the first solvent can then be withdrawn. This is
an extremely easy general way for obtaining a block amphipathic
polymer as the dispersed phase in accordance with the present
invention. As an example of the foregoing a block polymer of
polyisoprene-polystyrene-polyisoprene is formed by anionic
polymerization.
EXAMPLE XXXVIII
9.2 gs. of styrene are added to 60 cc. of tetrahydrofuran
containing 3.3 .times. 10.sup..sup.-4 mole of sodium naphthalene (a
catalyst) at -80.degree. C. in a three-neck round bottom flask
equipped with a mechanical stirrer, a thermometer and a nitrogen
inlet in a dry ice bath. The reaction is completed in 15 minutes,
resulting in the formation of a "living" polystyrene polymer. Upon
completion of polymerization 6.3 gs. of isoprene is added (still at
-80.degree.C.) and the isoprene polymerizes on the living ends of
the polystyrene to form a block polymer. The now living ends of
this block polymer, which block polymer is solvated by the
tetrahydrofuran, are then grafted on to a suitable backbone polymer
as by reacting at room temperature with 3 gs. of the precursor
solution of EXAMPLE XVIII to form the amphipathic polymer. Said
backbone (precursor) polymer likewise is solvated by the
tetrahydrofuran and such polymer is made the solvated phase of a
non-solvent for the block polymer of the system. Thereby the block
polymer moiety is desolvated. The non-solvent employed is OMS which
is added at room temperature to the solvated poly
(styrene/isoprene)/poly (lauryl methacrylate - glycidyl
methacrylate - methacrylic acid -- p-phenylazoacrylanilide)
amphipathic polymer to form a latex. To this colored
(golden-yellow) latex is added 2 gs. of a 1% solution of the
aluminum salt of 3,5-di-t-butyl gamma resorcylic acid to form a
toner concentrate. Fifteen gs. of the concentrate is diluted with
2000 mls. of OMS to form a working toner bath. When this toner is
employed by itself as a toner bath in a Dennison Standard Book
Copier good yellow prints are obtained.
EXAMPLE XXXIX
One hundred grams of the latex produced in EXAMPLE XXVII is placed
in a 500 mls. 3-neck round bottom open top flask equipped with a
stirrer, a reflux condenser and a thermometer, and 1.2 gs. of
Victoria Green (C.I. No. 42000B), 2.4 gs. Bismarck Brown (C.I. No.
21010B) and 0.3 g. Rhodamine Base (C.I. No. 45170B) are added to
it. The temperature is raised to 80.degree..+-.5.degree. C. and
held there for two hours. The black latex which results is cooled
and filtered through a 200 mesh nylon cloth to remove residual dye.
To this colored latex is added 5 mls. of aluminum dresinate
solution, 10% by weight in Isopar H, to form a toner concentrate.
To form a working toner bath, six grams of this concentrate is
diluted with 2000 mls. Isopar H. When used by itself as a toner
bath in a Dennison Standard Book Copier, dense black prints are
obtained.
EXAMPLE XL
To 100 grams of the latex prepared in EXAMPLE XXV is added 5 mls.
of a 1% solution by weight of aluminum 3,5-diisopropylsalicylate in
Isopar G to form a toner concentrate. To use this concentrate as a
developer, 4 grs. thereof are added to 2000 mls. Isopar G. When
tested in a copier, such as the Scott 3D, images are obtained which
are shiny and visible by light reflected at an acute angle from the
image.
To prepare a hybrid toner embodying the present invention either of
two procedures preferably is employed. One is, as indicated
previously, simply to mix together a previously prepared liquid
toner and a previously prepared second liquid toner. Said liquid
toners can be incorporated in the hybrid toner over a wide range of
proportions varying from about 1/2 % to 99.5% of either liquid
toner with the remainder being the other liquid toner. Any suitable
mixing equipment, either mechanical or manual, can be employed. The
other method of preparation is to mix together with a suitable
liquid carrier all of the various constituents which, if properly
segregated, would form the first and second liquid toners.
At this time, it should be reiterated that the hybrid toner
preferably utilizes a liquid carrier which is common to both the
first and the second liquid toners, although this is not an
absolute necessity, and if two separate solvent systems are
employed they should be compatible. Moreover, preferably, although
not necessarily, the same charge director(s) is (are) used for both
toners. This makes it less likely that the two toners will be
non-compatible and also simplifies procedure where the hybrid toner
is made by directly mixing together all of the constituents thereof
rather than by first preparing the first liquid toner and the
second liquid toner separately and then mixing them together. In
addition, it should be observed that certain charge directors, when
used in combination, exert a synergistic effect. These have been
found to be charge directors which are solvated in the solvent
system. The synergism is not necessarily desirable inasmuch as the
effect of the charge director peaks on the density vs.
concentration of charge director curve and, therefore, because of
the synergism the amounts of charge director, where two or more of
these are employed, should be adjusted downwardly, such adjustment
being within the skill of workers in the art and having to be
selected differently for every mixture of such charge directors,
and being further dependent upon the concentration and kinds of
pigments and color agents employed. In the examples given
subsequently where plural charge directors are given for a single
hybrid toner, such adjustment to take synergistic effects into
account always has been made.
There are other considerations whic should be taken into account,
to wit, that the amphipathic molecule (latex) of the second liquid
toner is capable of functioning, at least in part, as a dispersant
for the first liquid toner so that it is within the ambit of this
invention to omit or reduce the amount of any other dispersant for
the first liquid toner, said complex molecule being sufficient with
certain other constituents of the first liquid toner to supply all
or part of the necessary dispersing capability. The color agent of
either of the two liquid toners can be omitted even if a visible
developed image is required inasmuch as one color agent can suffice
to supply the necessary visibility. However, it usually is
desirable for both toners to contain color agents which, in the
case of the amphipathic molecle, may be a polymeric moiety of the
complex molecule. The same color agent can serve as the color agent
for the two toners, e.g. as the color agent for the hybrid
toner.
Set forth below in two sections are examples of hybrid toners
embodying the present invention, the first section of examples
constituting mixtures of the first toner and the second toner which
are prepared by mixing together pre-prepared first and second
liquid toners. The second constitutes examples of hybrid toners
prepared by mixing together the constituents desired to be present
in the finished hybrid toner but without the previous preparation
of the first and second liquid toners separately from one
another.
The amounts of the different non-carrier constituents of the hybrid
toners are, like those of the first and the second liquid toners,
capable of so wide a variation that it is not meaningful to give
any specific ranges. However, as a guide, the following represent
approximately maximum and minimum amounts of the various
non-carrier constituents per liter of liquid toner in a working
hybrid toner bath.
For the fixer (as hereinbefore described) which is a separate
chemical compound or composition (a chemical entity separate from
the dispersant) from about 0.0025 g. to about 5 gs.
For the dispersant (as hereinbefore described) which is a chemical
compound or composition that is chemically separate from the fixer
from about 0.5 g. to about 5 gs. As to this dispersant it should be
noted that it may embrace the amphipathic molecule alone or in
combination with other dispersants.
For the color agent from about zero g. to about 1.0 g. It should be
noted that the absence of color agent is not particularly desirable
but is envisioned that no color agent be present in the hybrid
toner when the same is used in the preparation of a lithographic
master.
For the charge director from about 1 .times. 10.sup..sup.-6 g. to
about 10 gs.
For the complex amphipathic polymeric molecule from about 0.05 g.
to about 30 gs.
The balance of the hybrid toner constitutes the solvent system.
EXAMPLES OF HYBRID TONERS FORMED BY MIXING PREVIOUSLY FORMED FIRST
AND SECOND LIQUID TONER CONCENTRATES AND DILUTING SAME
EXAMPLE XLI
4.5 gs. of the first liquid toner concentrate of EXAMPLE VIII and
0.5 g. of the second liquid toner concentrate of EXAMPLE XXX are
added to 2000 mls. of Isopar G. The developer bath is either
prepared manually and then added to a copying machine or the
components thereof are added separately to the developing tray of a
copying machine such as, e.g. the SCM 44 Copier and mixed by the
action of the circulating pump. Black dense prints are obtained,
free from background.
EXAMPLE XLII
0.5 g. of the first liquid toner concentrate of EXAMPLE VIII and
4.5 gs. of the second liquid toner concentrate of EXAMPLE XXX are
added to 2000 mls. of Isopar G to form a working toner bath. When
tested in the SCM 44 Copier, dense blue black prints are
obtained.
EXAMPLE XLIII
In order to obtain a developer for use in the preparation of
lithographic masters, add 8.0 gs. of the second liquid toner
concentrate of EXAMPLE XXXIX and 0.04 g. of the first liquid toner
concentrate of EXAMPLE IX to 2000 mls. Isopar G. This developer
gives excellent results in an office copy machine, such as the
Scott 3-D copier.
EXAMPLE XLIV
In order to obtain a developer for use in the preparation of
microfiche images, add 4.0 gs. each of the first and second liquid
toner concentrates mentioned in EXAMPLE XLIII to 2000 mls. Isopar
G.
EXAMPLE XLV
The addition of 0.04 gs. of the first liquid toner concentrate of
EXAMPLE X and 8.0 gs. of the second liquid toner concentrate of
EXAMPLE XL to 2000 mls. of Isopar H gives a developer for the
Toshiba BD-32 Copier which gives excellent lithographic
masters.
EXAMPLES OF HYBRID TONERS FORMED BY MIXING CONSTITUENTS WITH A
SOLVENT SYSTEM DIRECTLY WITHOUT THE INTERMEDIATE STEPS OF
INDEPENDENTLY FORMING THE FIRST AND SECOND LIQUID TONERS
EXAMPLE XLVI
Ball mill the following ingredients together for 23 hours at
90.degree. F.
______________________________________ 100 gs. Dymerex 50 gs.
Pliolite VTAC-L 60 gs. Toner 8100 500 gs. Solvent 460
______________________________________
Then add 100 gs. Solvent 460 and ball mill at the same temperature
for an additional hour. To 145 gs. of the foregoing add 60 gs. of
the latex of EXAMPLE XXV (in addition to its functions as a major
constituent of the second liquid toner component, this latex acts
as a dispersent for the constituents of the first liquid toner
component) and 0.75 g. of aluminum stearate and ball mill for 18
hours at 90.degree. F. to form a hybrid toner concentrate. 5 gs. of
the hybrid concentrate is diluted with 2000 mls. Isopar K to form a
working hybrid toner bath which when used in a Dennison Mark I Book
Copier produces dense black prints, free from background.
Although in this specific example, the two toner components are
ball milled together at a somewhat elevated temperature, the
majority of hybrid toners formed by blending of mixtures of first
and second liquid toners are prepared by simple manual or automatic
agitation means at ambient temperatures.
EXAMPLE XLVII ______________________________________ 20 gs. Dymerex
10 gs. Pliolite VTAC-L 8 gs. GAF Black M Toner 120 gs. Solvent 460
1 g. Aluminum stearate 30 gs. Latex of EXAMPLE XXV
______________________________________
The above ingredients are ball miled at 90.degree. F. for 18 hours
to form a hybrid toner concentrate. To prepare the working hybrid
toner bath, 5 gs. of hybrid toner concentrate is dispersed in 2000
mls. isopar K. When used in a Dennison Mark I Book Copier, dense
black prints are obtained free from background. Note that the latex
also acts as a dispersant for the pigment and the charge
director.
EXAMPLE XLVIII ______________________________________ 20 gs.
Dymerex 10 gs. Pliolite VTAC-L 15 gs. GAF Black M Toner 120 gs.
Solvent 460 2 gs. Lube Oil 564 1 g. Aluminum stearate 30 gs. Latex
of EXAMPLE XXV ______________________________________
The above ingredients are ball milled at 90.degree. F. for 18 hours
to form a hybrid toner concentrate. When used at a concentration of
5 gs./2000 mls, Isopar G in a Savin 220 Copier, dense black prints
are obtained, free from background.
EXAMPLE XLIX ______________________________________ 25 gs.
Staybelite 80 gs. Latex of EXAMPLE XXXIX 12 gs. Toner 8100 3 gs.
Spirit Nigrosine SSB 6 gs. Raven 11 1 g. Aluminum stearate 20 gs.
Alkanol DOA 50 gs. Isopar G
______________________________________
The above formula is ball milled for 40 hours at ambient
temperature to form a hybrid toner concentrate. When used in a
Scott 3D Copier at a concentration of 4gs./2000 mls. Isopar G,
dense black background-free prints are obtained.
EXAMPLE L ______________________________________ 25 gs. Staybelite
6 gs. Latex of EXAMPLE XXXIX 12 gs. Toner 8100 3 gs. Spirit
Nigrosine SSB 6 gs. Raven 11 2 gs. Aluminum stearate 20 gs. Alkanol
DOA 50 gs. Isopar G ______________________________________
The above formula is ball milled for 40 hours at ambient
temperature to form a hybrid toner concentrate. When used in a
Savin 200 Copier at a concentration of 6 gs./2000 mls. Isopar G,
dense black background-free prints are obtained.
EXAMPLE LI ______________________________________ 25 gs. Staybelite
80 gs. Latex of EXAMPLE XX dyed with Victoria Blue BA Base, 4% by
weight 8 gs. Toner 8100 2 gs. Spirit Nigrosine SSB 4 gs. Statex
B-12 10 gs. Alkanol DOA 10 gs. Polymerized castor oil
______________________________________
The above ingredients are ball milled at 98.degree. F. for 30
hours. The output is cut with a mixture of:
______________________________________ 0.75 g. Aluminum stearate 10
gs. Polymerized castor oil 50 gs. Isopar K
______________________________________
and ball milled for an additional hour to form a hybrid toner
concentrate. When used at a concentration of 3 gs./2000 mls. Isopar
K in a Dennison Mark I Book Copier, dense black background-free
prints are obtained.
EXAMPLE LII ______________________________________ 950 gs. Latex of
EXAMPLE XX dyed with Victoria Blue BA Base, 4% by weight 20 gs.
Staybelite 8 gs. Toner 8100 2 gs. Spirit Nigrosine SSB 4 gs. Raven
11 8 gs. Alkanol DOA 8 gs. Polymerized castor oil
______________________________________
The above ingredients are ball milled at 100.degree. F. for 40
hours. When used at a concentration of 25 gs./2000 mls. Isopar G
with the addition of 10 drops of a 1% solution by weight in Isopar
G of the aluminum salt of 3,5 diisopropylsalicylic acid, in a
Toshibafax BD-32 Copier, excellent lithographic masters are
produced.
With the use of the novel hybrid toner three unusual effects have
been observed in connection with the preparation of developed
images which are to be used as lithographic masters after
etching.
The first of these concerns the "fill" which is the uniformity of
electrostatographic deposit over a solid colored area in such a
proportion that it is a reasonable facsimile of the original image
densitywise. It will be recalled that, using the first liquid toner
alone, the fill inwardly of the periphery of a colored zone of
reasonably large size was poor. However, when even small amounts,
e.g. as low as 1/2%, of the constituents of the second liquid toner
are present in the hybrid liquid toner the fill is sharply
bettered. The rate of improving the fill tapers off as larger
amounts of the constituents of the second liquid toner are
employed, and if this were the sole desideratum, it would be
desirable not to include predominant amounts or even large amounts
of the second liquid toner or its constituents in the hybrid liquid
toner for economical reasons solely, inasmuch as the cost of the
amphipathic molecule exceeds the cost of the fixer and dispersant
of the first liquid toner. However, there are other considerations
which will be mentioned below which govern the ratio of the
constituents of the two liquid toners in the hybrid toner and it is
observed that the use of larger amounts of the constituents of the
second liquid toner in the hybrid toner do not lessen the effect of
improvement in fill. Heretofore it has been proposed to use various
types of mechanical approaches to the solution of this problem
such, for instance, as the addition of development electrodes
submerged in the bath and adjacent the path of travel of the
immersed sheet carrier, but the results obtained thereby were
largely unsatisfactory, and the fact that such samll amounts of a
second liquid toner in the hybrid toner so easily provides the
desired fill was entirely unexpected. There is no explanation for
such phenomenon, that is to say, the influence of the amphipathic
polymeric molecule on the density of deposit of the pigment
particles of the first liquid toner on an electrostatic latent
image.
Another important improvement resulting from the combination of the
two toners and, specifically, the addition of the constituents of
the second liquid toner to the first liquid toner, is the
lengthening of the life of the developed image when employed as a
lithographic master. It has been found that, despite the short life
of lithographic masters prepared with the first type of liquid
toner, the life of a lithographic master prepared with the hybrid
toner is very substantially greater and, indeed, at least as great
as the life of the lithographic master prepared solely with the
second liquid toner; in other words, the mixing together of the two
liquid toners for the purpose of increasing fill does not degrade
the life of the lightographic master prepared with the hybrid toner
below the life of the lithographic master prepared with the second
liquid toner alone so that, by this invention, both the fill and
the length of life of a lithographic master can be bettered. In
order to secure usable results insofar as the length of the life of
a lithographic master is concerned, it is desirable to employ not
less than about 1 part of the constituents of the second liquid
toner to about 20 parts of the constituents of the first liquid
toner. In connection with the foregoing it will be appreciated that
these proportions may be adjusted depending upon the length of life
desired and the cost factors involved; that is to say, if it is
known that for a particular use a less than very lengthy life is
required of a lithographic master, it would be a needless
extravagance to use more of the constituents of the second liquid
toner than will produce such an extended life.
An additional advantage observed by employing the constituents of
both the first and the second liquid toners in a hybrid toner
either for use in preparing a lithographic master or for general
office copying purposes is that the presence of even small amounts
of the constituents of the first liquid toner very substantially
increases the edge contrast of a developed image, in other words,
the sharpness or snappiness of the developed image. Such
improvement in edge contrast is noticeable with even amounts as
small as 1/2% of the constituents of the first liquid toner in the
hybrid toner. However, again, the matter of economical
considerations usually will preclude the employment of very large
amounts of the constituents of the second liquid toner.
Nevertheless, this increase in sharpness is not destroyed by using
larger amounts of the constituents of the first liquid toner in the
hybrid toner.
A further advantage has been observed which results from the
presence of even small amounts of the constituents of the second
liquid tonner in the hybrid toner, this relating to the resistance
of the deposited image to the etching solvent. It is characteristic
of images deposited through employment of the first liquid toner
that unless the original is extremely even in density the etch
tends to attack lighter portions of the image and this results in
portions of the image becoming less oleophilic than other portions
so that the copies prepared with the lithographic master experience
loss of quality in comparison with the original. But the addition
of even very small amounts of the constituents of the second liquid
toner overcomes this drawback and it will be observed that the
developed images prepared with the hybrid toner have a substantial
uniformity of resistance to transformation by the etching solution
from the oleophilic state to the hydrophilic state. This effect is
not decreased by the presence of larger amounts of the constituents
of the second liquid toner in the hybrid toner.
The second special increased utility ensuing from the use of the
hybrid toner concerns the electrostatographic preparation of
microfiche images. Heretofore there has been no widely commercially
acceptable toner for electrostatographic creation of microfiche
images. When the first liquid toner was employed it was subject to
the aforementioned difficulty that the fixer had to be raised to
such elevated temperature during fusing that it rendered the
transparent thermoplastic carrier for the transparent
photoconductor dimensionally unstable. This resulted in the running
together or blurring of adjacent supposedly spaced portions of the
reproduced image with such a high loss of resolution that such
image had no commercial value. On the other hand, where the second
liquid toner was employed the edges of image portions were not
faithful reproductions of the corresponding edges of the original
so that here, too, there was a tendency to lose resolution due to a
wavering of the edges of the reproduction that was not present in
the original. One other toner had been proposed for electrostatic
creation of mmicrofiche images, which toner required several
minutes for setting after development. In the interim preceding
hardening of the image, the toner could not be touched and this was
an impractical approach under modernday labor conditions and
particularly where high speed reproductions were involved. All of
these defects have been overcome when the first and second liquid
toners are conjointly used in a hybrid toner. For an unexplainable
reason or reasons the presence of the constituents of the first
liquid toner has been found to cause the edge portions of the
developed image to be faithful facsimiles of the edge portions of
the original, this being true where even the minimal amounts above
mentioned of the first liquid toner are employed. Conversely, the
presence of even the minimal amounts of the second liquid toner
have been found to enable the image to be fixed quickly and firmly
at temperatures below those necessary for fixing the first liquid
toner and below that which will render the thermoplastic
transparent carrier for an organic transparent photoconductor
dimensionally unstable. It is not known whether this decrease in
setting temperature is due to a lower fusing point for the fixative
moiety of the amphipathic molecule or to the ability of the
amphipathic molecule to form a solvent-induced bond with the
aforesaid thermoplastic carrier, or for some other reason not
known, but, be that as it may, the physical result is present and
for the first time enables a microfiche image to be created
speedily and at a low enough temperature not to affect resolution
so that the resolution capability of the final
electrostatographically produced image will be a function solely of
the resolution obtainable with the original at the optical
reduction ratio employed and will in no wise be deleteriously
affected by the reproduction process.
It thus will be seen that there is provided a system which achieves
the various objects of the invention and which is well adapted to
meet the conditions of practical use.
As various possible embodiments might be made of the above
invention, and as various changes might be made in the embodiments
above set forth, it is to be understood that all matter herein
described is to be interpreted as illustrative and not in a
limiting sense.
* * * * *